Post on 30-May-2018
Research ArticleSpin-Glass Behavior Magnetic and IR Spectroscopy Analysis ofMultimetallic Compound Ni025Mn125[Fe(CN)6]middot61H2O
Qing Lin12 Xiaofang Liu1 Yun He1 Haifu Huang13 and Xingcan Shen4
1College of Physics and Technology Guangxi Normal University Guilin 541004 China2Department of Information Technology Hainan Medical College Haikou 571101 China3Department of Physics Nanjing University Nanjing 210093 China4School of Chemistry and Chemical Engineering Guangxi Normal University 541004 Guilin China
Correspondence should be addressed to Yun He hygxnueducn
Received 5 June 2014 Accepted 2 July 2014
Academic Editor Qingrui Zhang
Copyright copy 2015 Qing Lin et alThis is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
Multimetallic Prussian blue compound Ni025
Mn125
[Fe(CN)6]sdot61H
2O has been prepared by coprecipitation The temperature-
dependent magnetic susceptibilities show the magnet transition for the compound at 85 K According to DC variable-temperaturemagnetic susceptibility paramagnetic Curie temperature 120579 is minus932 K The observed value of coercive field (Hc) and the remanentmagnetization (Mr) for the compound are 032 KOe and 036 120583B According to study of zero-field-cooled (ZFC) and field-cooled(FC) magnetization curves and AC magnetization curves there exists a spin-glass behaviour in the compound which exhibitsfreezing temperature 119879
119892= 776K below magnetic transition 119879
119862= 85K that glass behavior is termed ldquoreentrantrdquo spin glass
1 Introduction
Recently molecule-based magnets which can be synthe-sized by chemical process and have a main property ofsupramolecular structure exhibit magnetic properties dueto magnetic exchange interaction between magnetic ions[1ndash3] The design and synthesis of molecule-based magnetshave become one of the research foci on the physics andchemistry Ones have attracted extensive attention recentlyowe to the high 119879
119862molecular ferromagnets had been dis-
covered and the molecule-based magnets show a kinds offascinating magnetic phenomenon such as photomagneticeffect thermal induced magnetic properties and magnetic-pole reversal which have important potential application[4ndash6] Among various types of molecule-based magnetismmaterials Prussian blue analogues AP[B(CN)6]qsdot119909H2O [4](molecular structure of Prussian blue analogue compound asshown in Figure 1) play an important role due to their specialstructure and outstanding magnetic properties as molecule-based magnets The multimetal Prussian blue compoundNi025
Mn125
[Fe(CN)6]sdot61H
2Owas synthesized and has been
studied for its magnetic properties through elemental anal-ysis IR Mossbauer spectrum magnetic measurements andso forth
2 Experimental
21 Materials and Physical Measurements NiCl2sdot6H2O
Mn(SO4)2sdot6H2O and K
3Fe(CN)
6are of reagent grade and
without further purification Elemental analyses (C Hand N) were performed on Perkin-Elmer 2400 II analyserIR spectrum was recorded on a Perkin-Elmer FT-IRspectrophotometer as KBr pellet in the 4000sim400 cmminus1range Magnetization measurements were measured by aQuantum Design MPMS-7S superconducting quantuminterference device (SQUID) magnetometer in the scope of2ndash300K
22 Synthesis of Ni025
Mn125
[Fe(CN)6]sdot61H
2O Polycrys-
talline samples of Ni025
Mn125
[Fe(CN)6]sdot61H
2O have been
Hindawi Publishing CorporationJournal of SpectroscopyVolume 2015 Article ID 385215 6 pageshttpdxdoiorg1011552015385215
2 Journal of Spectroscopy
A C N B
Figure 1 Structure of Prussian blue analog AP[B(CN)6]qsdot119909H2O
prepared in coprecipitation method A mixture of aque-ous solutions of Co(NO
3)2(25mL 025mmol) and NiSO
4
(125mL 125mmol) was poured in aqueous solution ofK3[Fe(CN)
6] (100mL 1mmol) Then the mixture solution
was left to stand at room temperature for an appropriateperiod of time until those reactants were finished A lightbrown precipitation was obtained and precipitation then wasfiltered washed many times with demineralized water andfinally dried under IR lamp for about 50 minutes Elementalanalysis to measure C H and Nmass ratio found C 1744H 309 N 2123 calculation C 1779 H 303 N2074
3 Results and Discussion
31 IR Spectrum Analysis IR spectrum of the compoundhas been recorded over the 400ndash4000 cmminus1 range shownin Figure 2 It shows two obvious bands at 207501 and215174 cmminus1 indicating the existence of two types of cyanidegroups in the crystal lattice of compound [7ndash9] Compoundswith CNminus functional group are easily identified by theirstretching frequencies in 2200ndash2000 cmminus1 range which areconsistent with the formation of bridging cyanide groupsand there are two different coordination environmentsMoreover the broad peaks at 343290 cmminus1 and 161502 cmminus1are assigned to the v (OndashH) of the crystal water stretchingvibrations
32 DC Magnetic Susceptibility The magnetic susceptibilityof the compound was measured from 2K to 300K in 250Oefield Figure 3 shows the field-cooled magnetization (119872)versus temperature (119879) curve and a sharp increase in 119872 isobserved around 21 K Magnetic transition temperature wasestimated from minima of 119889119872119889119879 versus 119879 curve which
4000 3000 2000 100020
25
30
35
40
343290
215174
207501
161502
T(
)
(cmminus1)
Figure 2 FT-IR spectrum of the compound
0 50 100 150 200 250 300
000
001
002
003
004
005M
(em
u)
M (emu)
T (K)
Figure 3119872 versus 119879 for the compound
corresponds to the steepest increase of magnetization withdecreasing temperature (as shown in Figure 4) The phasetransition the compound undergoes from a paramagnetic toferroferrimagnetic type is about 85 K which is lower thanthat for the parent compound Ni
15[Fe(CN)
6]sdotxH2O (119879119862=
236K) [10]The inverse susceptibility as a function of temperature in
the paramagnetic state is shown in Figure 5 The curve risesslowly with decrease of temperature from 300 to 25K andthen rises sharply as temperature continues to decrease The120594
119898shows a sharp maximum at 2K This kind of behaviour is
a characteristic of a ferromagnet The magnetic order resultsfrom the combination of ferromagnetic and neighboringantiferromagnetic interactions Furthermore high tempera-ture DC susceptibility (120594
119898= 119872119867) is found to obey the
Curie-Weiss lawFigure 6 shows the temperature dependence of 120594
119898
minus1 inthe temperature range of 20ndash280K The Curie constant (119862)
Journal of Spectroscopy 3
0 5 10 15 20 25 30 35 40 45 50
0000
minus0005
minus0035
minus0030
minus0025
minus0020
minus0015
minus0010
T (K)
dMdT
Tc = 85K
Figure 4 119889119872119889119879 versus 119879 for the compound
0 50 100 150 200 250 300
00
05
10
15
20
25
T (K)
120594M
(cm3middotm
olminus1)
Figure 5 120594119898versus 119879 for the compound
0 50 100 150 200 250 300
0
10
20
30
40
50
Data
120594Mminus1
(cmminus3middotm
ol)
120579 = minus932K
T (K)
Linear fit
Figure 6 120594119898
minus1 versus 119879 for the compound
0 50 100 150 200 250 3004
6
8
10
12
14
16
120594MT
(cm3middotm
olminus1middotK
)
120594MT
T (K)
Figure 7 120594119898119879 versus 119879 for the compound
and the Curie-Weiss temperature (120579) are estimated by a linearfitting of 1120594 = (119879 minus 120579)119862 at the linear region [8ndash10] Fittingyielded that the Curie constant 119862 = 1520 cm3sdotKsdotmolminus1 andparamagnetic Curie temperature 120579 = minus932K The values of119879
119862 120579 and 119862 are different from those values for ferrimagnet
Ni15[Fe(CN)
6]sdotxH2O [10] andMn
3[Fe (CN)
6]2sdot15H2O (119879119862=
9K) [11]A curve of 120594
119898119879 versus 119879 is shown in Figure 7 and
the 120594119898119879 value at room temperature is 57 cm3sdotKsdotmolminus1
Upon lowering the temperature 120594119898119879 value sharply increases
after 15 K with a further decrease of the temperature The120594
119898119879 shows a sharp maximum value of 353 cm3sdotKsdotmolminus1
at 9 K and then finally decreases more rapidly on furthercooling For a ferromagnetic compound 120594
119898119879 versus 119879 curve
reaches a minimum before rising around magnetic orderingtemperature [12ndash14]
A curve of 120583eff versus 119879 is shown in Figure 8The effectivemoment 120583eff first slowly decreases to reach a minimum of647 120583B at 23 K and then sharply increases to reachmaximumof 1683 120583B at 9 K and final decrease at lower tempera-ture indicating antiferromagnetic interaction between para-magnetic centers [15ndash17] Magnetic transition temperaturewas estimated from minimum of 119889120583eff119889119879 versus 119879 curvewhich corresponds to the steepest increase of magnetizationwith decreasing temperature (as shown in Figure 6 insertplot of 119889120583eff119889119879 versus 119879) The compound undergoes aparamagnetic to ferroferrimagnetic type phase transitionat 95 K which could be attributed to an intermolecularantiferromagnetic interaction andor a zero-field splitting(ZFS) effect This kind of behaviour is a characteristic of aferromagnet [18 19]
33 Zero-Field-Cooled (ZFC) and Field-Cooled (FC) Mag-netization Figure 9 shows the curves of zero-field-cooled(ZFC) and field-cooled (FC)magnetization of the compoundat different field 119867 = 20 100 250 and 500Oe Thevalues of 119872 increase and exhibit weak irreversibility in
4 Journal of Spectroscopy
0 50 100 150 200 250 300
6
8
10
12
14
16
18
0 5 10 15 20 25 30 35 40 45 50
0
1
2
Data
T (K)
T (K)
d120583
effdT
Tc = 95K
minus1
minus2
minus3
120583ef
f(120583
120573)
Figure 8 120583eff versus 119879 for the compound (insert plot of 119889120583eff119889119879versus 119879)
2 4 6 8 10 12 14 16 18 20
0
500
1000
1500
2000
2500
3000
3500
4000
20Oe100Oe
250Oe500Oe
20Oe100Oe
250Oe500Oe
MFC
MZFC
M(c
m3middotGmiddotm
olminus1)
T (K)
Figure 9 ZFC and FC magnetization curves with different field
the field-cooled (FC) magnetization curves below 119879119862= 12K
There is a clear bifurcation phenomenon of the field-cooled(119872FC) and zero-field-cooled (119872ZFC) magnetization curves119879irr is a bifurcation temperature point of which FC and ZFCmagnetization curves separate out In addition the behaviorthat119872ZFC exhibits a maximum below 119879irr is attributed to thecooperative freezing of spin glass (as shown in Figure 10)The irreversible behavior of119872 and shift of bifurcation pointto lower temperature with increasing 119867 are characteristicfor spin glasses [10 11] It may be reasonable that thesemetal ions FeIII NiII and MnII through cyanide-bridgedligand have the coexistence of different valence states or spinstates the presence of inhomogeneity and inherent structuraldisorder which propagate possibly the ferromagnetic andantiferromagnetic exchange interaction via bridging cyanide
0 100 200 300 400 500 600
5
6
7
8
9
10
11
12
13
14
TirrTmax
T(K
)
H (Oe)
Linear fit
Figure 10 119879irr and 119879max versus119867 for the compound
2 4 6 8 10 12 14 16
0
1
2
3
4
5
10Hz32Hz100Hz
320Hz1000Hz
120594M
(cm3middotm
olminus1)
T (K)
120594998400M
120594998400M
Figure 11 1205941015840(119879) and 12059410158401015840(119879) curves of AC magnetic susceptibility ofthe compound with different frequencies
and there exist a structural disorder and a certain contentof crystallization water which lead to the weak spin-orbitcoupling The spin-glass property is due to magnetic domainkinetics under different cooling conditions and the presenceof available vacant sites in the lattice for the water molecules
34 AC Magnetic Susceptibility It was also confirmed thatthere exists a spin-glass behavior in the compound throughAC magnetization curves The AC magnetic susceptibilityof the compound was measured at 4Oe AC amplitude withzero-applied DC field when varying the frequencies (119891) from10 to 1000Hz as shown in Figure 11 The temperature depen-dence of zero-static field AC magnetic susceptibilities shows
Journal of Spectroscopy 5
10 15 20 25 30
7773
7776
7779
7782
7785
7788
7791
Data
log(w)
Tf
(K)
Linear fit
Figure 12 The log(119908) dependence of the 119879119891
that the in-phase component (1205941015840) has a maximum at about77 K for frequencies of 10 32 100 320 and 997Hz and that asignificant out-of-phase component (12059410158401015840) appears confirm-ing the long-range ferromagnetic ordering On decreasingtemperature the in-phase signals 1205941015840 increase abruptly ataround 12K reach the maximum at about 77 K and thendecrease slowlyThe out-of-phase signals 12059410158401015840 increase steadilyto the maximum around 8K and then decrease slowly asshown in Figure 11 The fact that the 1205941015840 (119879) clearly shows afrequency dependence is typically assigned to spin glasses [1213] The freezing temperature (119879
119891) 119879119891= 77K is defined by
the maximum in the 119909AC(119879) plot at low frequency It under-goes a paramagnetic to ferromagnetic transition at around77 K In fact the temperature value of the maximum of 120594 at agiven frequency (119899) corresponds to the blocking temperature(119879119873= 119879max) whereby it is assumed that the switching
of the oscillating AC field matches the relaxation rate ofthe magnetization
Proportional relationship between freezing temperature119879
119891and logarithm of frequency in spin-glass system can be
described by quantifying the frequency dependence throughthe ratio 119888 which can be written as 119888 = Δ119879
119891119879
119891Δ log119908
119879
119891(119908) versus log(119908) is shown in Figure 12 The value of
freezing temperature of zero frequency is 119879119892= 776K by
extrapolation method and the value of 119888 obtained for thecompound is 00011 which fall within the range typical for theconventional spin-glass system (10minus2-10minus3) Surprisingly boththe in-phase and out-of-phase signals (1205941015840 and 12059410158401015840) go througha maximum with strong frequency dependence Both in thereal and in the imaginary components the peaks shift tolower temperatures with decreasing frequencies Howeverthe intensities of the peaks behave differently While theintensity of the peaks for the real component increases withdecreasing frequencies in the imaginary component theintensity of the peaks decreases with decreasing frequencies
0 10 20 30 40 50
00
05
10
15
20
25
30
35
40
H (kOe)
minus05
M(120583
120573)
Figure 13 Field-dependent magnetization curves
0 2000 40000
2000
4000
6000
8000
minus4000 minus2000minus2000
minus4000
minus6000
minus8000
M(e
mu g
minus1)
H (Oe)
Figure 14 The hysteresis loop for the compound
This behaviour of 12059410158401015840 and 12059410158401015840 is typical of a spin-glassstate [16ndash19]
35 Field-Dependent Magnetization and Hysteresis BehaviorIn order to further understand the nature of magnetic order-ing the ferromagnetism behavior is characterized by themeasurements of field-dependent magnetization as shownin Figures 11 and 13 The observed 119872
119904value is 385 120583B
at 50 kOe but the compound does not reach full satura-tion and this behavior is likely to be related to the spin-glass behavior as well as the amount of spin and type ofcoupling in the compounds Ni
15[Fe(CN)
6]sdotxH2O [18] and
Mn3[Fe(CN)
6]2sdot15H2O [10]
Ferromagnetism in thecompoundNi025
Mn125
[Fe(CN)6]sdot
61H2O is also supported by hysteresis loop curves measured
at 4 K as shown in Figure 14 The coercive field (119867119888) was
032 kOe which was smaller than that of the compoundNi15[Fe(CN)
6]sdotxH2O (119867119888= 25 KOe44 K) [12] The rema-
nent magnetization (119872119903) with 032 120583B for the compound It is
also obtained by the hysteresis loop curvesTherefore synthesis ideas of molecular alloy magnet can
be regarded as a synthesis method to expand a new typeof magnetic functional materials whose magnetic properties
6 Journal of Spectroscopy
can be tuned and controlled by changing the composition ofdifferent transition metal cations [15 17ndash19]
4 Conclusion
We have reported a detailed investigation of magneticproperties of multimetallic Prussian blue compoundsNi025
Mn125
[Fe(CN)6]sdot61H
2O The temperature-depend-
ent magnetic susceptibilities show the magnetism tran-sition for the compound at 85 K The Curie constant(119862 = 1520 cm3sdotKsdotmolminus1) and the Curie-Weiss temperature(120579 = minus932K) are obtained through a linear fitting of1120594 = (119879 minus 120579)119862 at the linear region [8ndash10]
The observed values of coercive field (119867119888) and remanent
magnetization (119872119903) for the compound are 032 KOe and
036 120583119861 Moreover there exists a spin-glass behaviour in the
compound according to study of zero-field-cooled (ZFC) andfield-cooled (FC) magnetization curves and AC magnetiza-tion curves which exhibits freezing temperature119879
119892= 776K
below magnetic transition 119879119888= 85K Such a glass behavior
is termed ldquoreentrantrdquo spin glass It was also confirmed by thebehaviour of 12059410158401015840 and 12059410158401015840 which go through a maximum withstrong frequency dependence
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
This work was financially supported by the National NaturalScience Foundation of China (nos 11164002 and 11364004)and Innovation Project of Guangxi Graduate Educationunder Grant no 0991092
References
[1] J M Manriquez G T Yee R S Mclean A J Epsteinand J S Miller ldquoA room-temperature molecularorganic-basedmagnetrdquo Science vol 252 no 5011 pp 1415ndash1417 1991
[2] S Ferlay T Mallah R Ouahes P Veillet and M Verdaguer ldquoAroom-temperature organometallic magnet based on Prussianbluerdquo Nature vol 378 no 6558 pp 701ndash703 1995
[3] O Sato T Iyoda A Fujishima and K Hashimoto ldquoElec-trochemical tunable magnetic phase transition in a high-Tcchromium cyanide thin filmrdquo Science vol 271 no 5245 pp 49ndash51 1996
[4] M Giorgetti ldquoA review on the structural studies of batteriesand host materials by X-ray absorption spectroscopyrdquo ISRNMaterials Science vol 2013 Article ID 938625 22 pages 2013
[5] S-I Ohkoshi T Iyoda A Fujishima and K HashimotoldquoMagnetic properties of mixed ferro-ferrimagnets composed ofPrussian blue analogsrdquoPhysical ReviewBCondensedMatter andMaterials Physics vol 56 no 18 pp 11642ndash11652 1997
[6] S Ohkoshi O Sato T Iyoda A Fujishima and K HashimotoldquoTuning of superexchange couplings in amolecule-based ferro-ferrimagnet (Ni119868119868
119909Mn1198681198681minus119909
) 15 [Cr119868119868119868 (CN)6]rdquo Inorganic Chem-
istry vol 36 pp 268ndash269 1997
[7] S-I Ohkoshi Y Abe A Fujishima and K Hashimoto ldquoDesignand preparation of a novelmagnet exhibiting two compensationtemperatures based on molecular field theoryrdquo Physical ReviewLetters vol 82 no 6 pp 1285ndash1288 1999
[8] A Kumar and S M Yusuf ldquoMagnetic properties of multi-metalPrussian Blue analogue Co
075Ni075
[Fe(CN)6]sdot68H
2Ordquo Physica
B Condensed Matter vol 362 no 1ndash4 pp 278ndash285 2005[9] A Kumar S M Yusuf and L Keller ldquoNeutron diffraction study
of molecular magnetic compound Ni1125
Co0375
[Fe(CN)6]sdot
64H2Ordquo Physica B vol 385-386 pp 444ndash446 2006
[10] O Kahn S J Miller and F Palacio Eds Magnetic MolecularMaterials vol 198 of NATO ASI Series E Plenum New YorkNY USA 1991
[11] S Juskzyk C Johanssont M Hansont A Ratusmas and GMakckill ldquoFerromagnetism of the Me
3[Fe(CN)
6]sdotH2o com-
pounds where Me = Ni and Cordquo Journal of Physics CondensedMatter vol 6 pp 5697ndash5765 1994
[12] J S Miller and A J Epstein ldquoOrganic and organometallicmolecular magnetic materials-designer magnetsrdquo AngewandteChemie International Edition in English vol 33 no 4 pp 385ndash415 1994
[13] O Kahn Molecular Magnetism Wiley-VCH New York NYUSA 1993
[14] W E Buschmann and J S Miller ldquoMagnetic ordering and spin-glass behavior in first-row transition metal hexacyanoman-ganate(IV) Prussian Blue analoguesrdquo Inorganic Chemistry vol39 no 11 pp 2411ndash2421 2000
[15] Y He Y-D Dai H-B Huang J Lin and Y-F Hsia ldquoSpin-glass state and ferromagnetic order in Cu(II)-Fe(III) cyanidesrdquoChinese Physics vol 13 no 5 pp 746ndash749 2004
[16] H Huang L Wei Y He X Li and F Liang ldquoFerromagneticorder and spin-glass behavior in multi-metallic compoundNi1125
Co0375
[Fe(CN)6] sdot 68H
2Ordquo Current Applied Physics vol
9 no 5 pp 1160ndash1164 2009[17] S-I Ohkoshi S Yorozu O Sato T Iyoda A Fujishima and
K Hashimoto ldquoPhotoinduced magnetic pole inversion in aferro-ferrimagnet (FeII040MnII
060)15CrIII(CN)6rdquo Applied Physics
Letters vol 70 no 8 pp 1040ndash1042 1997[18] D Sherrington and S Kirkpatrick ldquoSolvable model of a spin-
glassrdquo Physical Review Letters vol 35 no 26 pp 1792ndash17961975
[19] M Gabay and G Toulouse ldquoCoexistence of spin-glass andferromagnetic orderingsrdquo Physical Review Letters vol 47 no 3pp 201ndash204 1981
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CatalystsJournal of
2 Journal of Spectroscopy
A C N B
Figure 1 Structure of Prussian blue analog AP[B(CN)6]qsdot119909H2O
prepared in coprecipitation method A mixture of aque-ous solutions of Co(NO
3)2(25mL 025mmol) and NiSO
4
(125mL 125mmol) was poured in aqueous solution ofK3[Fe(CN)
6] (100mL 1mmol) Then the mixture solution
was left to stand at room temperature for an appropriateperiod of time until those reactants were finished A lightbrown precipitation was obtained and precipitation then wasfiltered washed many times with demineralized water andfinally dried under IR lamp for about 50 minutes Elementalanalysis to measure C H and Nmass ratio found C 1744H 309 N 2123 calculation C 1779 H 303 N2074
3 Results and Discussion
31 IR Spectrum Analysis IR spectrum of the compoundhas been recorded over the 400ndash4000 cmminus1 range shownin Figure 2 It shows two obvious bands at 207501 and215174 cmminus1 indicating the existence of two types of cyanidegroups in the crystal lattice of compound [7ndash9] Compoundswith CNminus functional group are easily identified by theirstretching frequencies in 2200ndash2000 cmminus1 range which areconsistent with the formation of bridging cyanide groupsand there are two different coordination environmentsMoreover the broad peaks at 343290 cmminus1 and 161502 cmminus1are assigned to the v (OndashH) of the crystal water stretchingvibrations
32 DC Magnetic Susceptibility The magnetic susceptibilityof the compound was measured from 2K to 300K in 250Oefield Figure 3 shows the field-cooled magnetization (119872)versus temperature (119879) curve and a sharp increase in 119872 isobserved around 21 K Magnetic transition temperature wasestimated from minima of 119889119872119889119879 versus 119879 curve which
4000 3000 2000 100020
25
30
35
40
343290
215174
207501
161502
T(
)
(cmminus1)
Figure 2 FT-IR spectrum of the compound
0 50 100 150 200 250 300
000
001
002
003
004
005M
(em
u)
M (emu)
T (K)
Figure 3119872 versus 119879 for the compound
corresponds to the steepest increase of magnetization withdecreasing temperature (as shown in Figure 4) The phasetransition the compound undergoes from a paramagnetic toferroferrimagnetic type is about 85 K which is lower thanthat for the parent compound Ni
15[Fe(CN)
6]sdotxH2O (119879119862=
236K) [10]The inverse susceptibility as a function of temperature in
the paramagnetic state is shown in Figure 5 The curve risesslowly with decrease of temperature from 300 to 25K andthen rises sharply as temperature continues to decrease The120594
119898shows a sharp maximum at 2K This kind of behaviour is
a characteristic of a ferromagnet The magnetic order resultsfrom the combination of ferromagnetic and neighboringantiferromagnetic interactions Furthermore high tempera-ture DC susceptibility (120594
119898= 119872119867) is found to obey the
Curie-Weiss lawFigure 6 shows the temperature dependence of 120594
119898
minus1 inthe temperature range of 20ndash280K The Curie constant (119862)
Journal of Spectroscopy 3
0 5 10 15 20 25 30 35 40 45 50
0000
minus0005
minus0035
minus0030
minus0025
minus0020
minus0015
minus0010
T (K)
dMdT
Tc = 85K
Figure 4 119889119872119889119879 versus 119879 for the compound
0 50 100 150 200 250 300
00
05
10
15
20
25
T (K)
120594M
(cm3middotm
olminus1)
Figure 5 120594119898versus 119879 for the compound
0 50 100 150 200 250 300
0
10
20
30
40
50
Data
120594Mminus1
(cmminus3middotm
ol)
120579 = minus932K
T (K)
Linear fit
Figure 6 120594119898
minus1 versus 119879 for the compound
0 50 100 150 200 250 3004
6
8
10
12
14
16
120594MT
(cm3middotm
olminus1middotK
)
120594MT
T (K)
Figure 7 120594119898119879 versus 119879 for the compound
and the Curie-Weiss temperature (120579) are estimated by a linearfitting of 1120594 = (119879 minus 120579)119862 at the linear region [8ndash10] Fittingyielded that the Curie constant 119862 = 1520 cm3sdotKsdotmolminus1 andparamagnetic Curie temperature 120579 = minus932K The values of119879
119862 120579 and 119862 are different from those values for ferrimagnet
Ni15[Fe(CN)
6]sdotxH2O [10] andMn
3[Fe (CN)
6]2sdot15H2O (119879119862=
9K) [11]A curve of 120594
119898119879 versus 119879 is shown in Figure 7 and
the 120594119898119879 value at room temperature is 57 cm3sdotKsdotmolminus1
Upon lowering the temperature 120594119898119879 value sharply increases
after 15 K with a further decrease of the temperature The120594
119898119879 shows a sharp maximum value of 353 cm3sdotKsdotmolminus1
at 9 K and then finally decreases more rapidly on furthercooling For a ferromagnetic compound 120594
119898119879 versus 119879 curve
reaches a minimum before rising around magnetic orderingtemperature [12ndash14]
A curve of 120583eff versus 119879 is shown in Figure 8The effectivemoment 120583eff first slowly decreases to reach a minimum of647 120583B at 23 K and then sharply increases to reachmaximumof 1683 120583B at 9 K and final decrease at lower tempera-ture indicating antiferromagnetic interaction between para-magnetic centers [15ndash17] Magnetic transition temperaturewas estimated from minimum of 119889120583eff119889119879 versus 119879 curvewhich corresponds to the steepest increase of magnetizationwith decreasing temperature (as shown in Figure 6 insertplot of 119889120583eff119889119879 versus 119879) The compound undergoes aparamagnetic to ferroferrimagnetic type phase transitionat 95 K which could be attributed to an intermolecularantiferromagnetic interaction andor a zero-field splitting(ZFS) effect This kind of behaviour is a characteristic of aferromagnet [18 19]
33 Zero-Field-Cooled (ZFC) and Field-Cooled (FC) Mag-netization Figure 9 shows the curves of zero-field-cooled(ZFC) and field-cooled (FC)magnetization of the compoundat different field 119867 = 20 100 250 and 500Oe Thevalues of 119872 increase and exhibit weak irreversibility in
4 Journal of Spectroscopy
0 50 100 150 200 250 300
6
8
10
12
14
16
18
0 5 10 15 20 25 30 35 40 45 50
0
1
2
Data
T (K)
T (K)
d120583
effdT
Tc = 95K
minus1
minus2
minus3
120583ef
f(120583
120573)
Figure 8 120583eff versus 119879 for the compound (insert plot of 119889120583eff119889119879versus 119879)
2 4 6 8 10 12 14 16 18 20
0
500
1000
1500
2000
2500
3000
3500
4000
20Oe100Oe
250Oe500Oe
20Oe100Oe
250Oe500Oe
MFC
MZFC
M(c
m3middotGmiddotm
olminus1)
T (K)
Figure 9 ZFC and FC magnetization curves with different field
the field-cooled (FC) magnetization curves below 119879119862= 12K
There is a clear bifurcation phenomenon of the field-cooled(119872FC) and zero-field-cooled (119872ZFC) magnetization curves119879irr is a bifurcation temperature point of which FC and ZFCmagnetization curves separate out In addition the behaviorthat119872ZFC exhibits a maximum below 119879irr is attributed to thecooperative freezing of spin glass (as shown in Figure 10)The irreversible behavior of119872 and shift of bifurcation pointto lower temperature with increasing 119867 are characteristicfor spin glasses [10 11] It may be reasonable that thesemetal ions FeIII NiII and MnII through cyanide-bridgedligand have the coexistence of different valence states or spinstates the presence of inhomogeneity and inherent structuraldisorder which propagate possibly the ferromagnetic andantiferromagnetic exchange interaction via bridging cyanide
0 100 200 300 400 500 600
5
6
7
8
9
10
11
12
13
14
TirrTmax
T(K
)
H (Oe)
Linear fit
Figure 10 119879irr and 119879max versus119867 for the compound
2 4 6 8 10 12 14 16
0
1
2
3
4
5
10Hz32Hz100Hz
320Hz1000Hz
120594M
(cm3middotm
olminus1)
T (K)
120594998400M
120594998400M
Figure 11 1205941015840(119879) and 12059410158401015840(119879) curves of AC magnetic susceptibility ofthe compound with different frequencies
and there exist a structural disorder and a certain contentof crystallization water which lead to the weak spin-orbitcoupling The spin-glass property is due to magnetic domainkinetics under different cooling conditions and the presenceof available vacant sites in the lattice for the water molecules
34 AC Magnetic Susceptibility It was also confirmed thatthere exists a spin-glass behavior in the compound throughAC magnetization curves The AC magnetic susceptibilityof the compound was measured at 4Oe AC amplitude withzero-applied DC field when varying the frequencies (119891) from10 to 1000Hz as shown in Figure 11 The temperature depen-dence of zero-static field AC magnetic susceptibilities shows
Journal of Spectroscopy 5
10 15 20 25 30
7773
7776
7779
7782
7785
7788
7791
Data
log(w)
Tf
(K)
Linear fit
Figure 12 The log(119908) dependence of the 119879119891
that the in-phase component (1205941015840) has a maximum at about77 K for frequencies of 10 32 100 320 and 997Hz and that asignificant out-of-phase component (12059410158401015840) appears confirm-ing the long-range ferromagnetic ordering On decreasingtemperature the in-phase signals 1205941015840 increase abruptly ataround 12K reach the maximum at about 77 K and thendecrease slowlyThe out-of-phase signals 12059410158401015840 increase steadilyto the maximum around 8K and then decrease slowly asshown in Figure 11 The fact that the 1205941015840 (119879) clearly shows afrequency dependence is typically assigned to spin glasses [1213] The freezing temperature (119879
119891) 119879119891= 77K is defined by
the maximum in the 119909AC(119879) plot at low frequency It under-goes a paramagnetic to ferromagnetic transition at around77 K In fact the temperature value of the maximum of 120594 at agiven frequency (119899) corresponds to the blocking temperature(119879119873= 119879max) whereby it is assumed that the switching
of the oscillating AC field matches the relaxation rate ofthe magnetization
Proportional relationship between freezing temperature119879
119891and logarithm of frequency in spin-glass system can be
described by quantifying the frequency dependence throughthe ratio 119888 which can be written as 119888 = Δ119879
119891119879
119891Δ log119908
119879
119891(119908) versus log(119908) is shown in Figure 12 The value of
freezing temperature of zero frequency is 119879119892= 776K by
extrapolation method and the value of 119888 obtained for thecompound is 00011 which fall within the range typical for theconventional spin-glass system (10minus2-10minus3) Surprisingly boththe in-phase and out-of-phase signals (1205941015840 and 12059410158401015840) go througha maximum with strong frequency dependence Both in thereal and in the imaginary components the peaks shift tolower temperatures with decreasing frequencies Howeverthe intensities of the peaks behave differently While theintensity of the peaks for the real component increases withdecreasing frequencies in the imaginary component theintensity of the peaks decreases with decreasing frequencies
0 10 20 30 40 50
00
05
10
15
20
25
30
35
40
H (kOe)
minus05
M(120583
120573)
Figure 13 Field-dependent magnetization curves
0 2000 40000
2000
4000
6000
8000
minus4000 minus2000minus2000
minus4000
minus6000
minus8000
M(e
mu g
minus1)
H (Oe)
Figure 14 The hysteresis loop for the compound
This behaviour of 12059410158401015840 and 12059410158401015840 is typical of a spin-glassstate [16ndash19]
35 Field-Dependent Magnetization and Hysteresis BehaviorIn order to further understand the nature of magnetic order-ing the ferromagnetism behavior is characterized by themeasurements of field-dependent magnetization as shownin Figures 11 and 13 The observed 119872
119904value is 385 120583B
at 50 kOe but the compound does not reach full satura-tion and this behavior is likely to be related to the spin-glass behavior as well as the amount of spin and type ofcoupling in the compounds Ni
15[Fe(CN)
6]sdotxH2O [18] and
Mn3[Fe(CN)
6]2sdot15H2O [10]
Ferromagnetism in thecompoundNi025
Mn125
[Fe(CN)6]sdot
61H2O is also supported by hysteresis loop curves measured
at 4 K as shown in Figure 14 The coercive field (119867119888) was
032 kOe which was smaller than that of the compoundNi15[Fe(CN)
6]sdotxH2O (119867119888= 25 KOe44 K) [12] The rema-
nent magnetization (119872119903) with 032 120583B for the compound It is
also obtained by the hysteresis loop curvesTherefore synthesis ideas of molecular alloy magnet can
be regarded as a synthesis method to expand a new typeof magnetic functional materials whose magnetic properties
6 Journal of Spectroscopy
can be tuned and controlled by changing the composition ofdifferent transition metal cations [15 17ndash19]
4 Conclusion
We have reported a detailed investigation of magneticproperties of multimetallic Prussian blue compoundsNi025
Mn125
[Fe(CN)6]sdot61H
2O The temperature-depend-
ent magnetic susceptibilities show the magnetism tran-sition for the compound at 85 K The Curie constant(119862 = 1520 cm3sdotKsdotmolminus1) and the Curie-Weiss temperature(120579 = minus932K) are obtained through a linear fitting of1120594 = (119879 minus 120579)119862 at the linear region [8ndash10]
The observed values of coercive field (119867119888) and remanent
magnetization (119872119903) for the compound are 032 KOe and
036 120583119861 Moreover there exists a spin-glass behaviour in the
compound according to study of zero-field-cooled (ZFC) andfield-cooled (FC) magnetization curves and AC magnetiza-tion curves which exhibits freezing temperature119879
119892= 776K
below magnetic transition 119879119888= 85K Such a glass behavior
is termed ldquoreentrantrdquo spin glass It was also confirmed by thebehaviour of 12059410158401015840 and 12059410158401015840 which go through a maximum withstrong frequency dependence
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
This work was financially supported by the National NaturalScience Foundation of China (nos 11164002 and 11364004)and Innovation Project of Guangxi Graduate Educationunder Grant no 0991092
References
[1] J M Manriquez G T Yee R S Mclean A J Epsteinand J S Miller ldquoA room-temperature molecularorganic-basedmagnetrdquo Science vol 252 no 5011 pp 1415ndash1417 1991
[2] S Ferlay T Mallah R Ouahes P Veillet and M Verdaguer ldquoAroom-temperature organometallic magnet based on Prussianbluerdquo Nature vol 378 no 6558 pp 701ndash703 1995
[3] O Sato T Iyoda A Fujishima and K Hashimoto ldquoElec-trochemical tunable magnetic phase transition in a high-Tcchromium cyanide thin filmrdquo Science vol 271 no 5245 pp 49ndash51 1996
[4] M Giorgetti ldquoA review on the structural studies of batteriesand host materials by X-ray absorption spectroscopyrdquo ISRNMaterials Science vol 2013 Article ID 938625 22 pages 2013
[5] S-I Ohkoshi T Iyoda A Fujishima and K HashimotoldquoMagnetic properties of mixed ferro-ferrimagnets composed ofPrussian blue analogsrdquoPhysical ReviewBCondensedMatter andMaterials Physics vol 56 no 18 pp 11642ndash11652 1997
[6] S Ohkoshi O Sato T Iyoda A Fujishima and K HashimotoldquoTuning of superexchange couplings in amolecule-based ferro-ferrimagnet (Ni119868119868
119909Mn1198681198681minus119909
) 15 [Cr119868119868119868 (CN)6]rdquo Inorganic Chem-
istry vol 36 pp 268ndash269 1997
[7] S-I Ohkoshi Y Abe A Fujishima and K Hashimoto ldquoDesignand preparation of a novelmagnet exhibiting two compensationtemperatures based on molecular field theoryrdquo Physical ReviewLetters vol 82 no 6 pp 1285ndash1288 1999
[8] A Kumar and S M Yusuf ldquoMagnetic properties of multi-metalPrussian Blue analogue Co
075Ni075
[Fe(CN)6]sdot68H
2Ordquo Physica
B Condensed Matter vol 362 no 1ndash4 pp 278ndash285 2005[9] A Kumar S M Yusuf and L Keller ldquoNeutron diffraction study
of molecular magnetic compound Ni1125
Co0375
[Fe(CN)6]sdot
64H2Ordquo Physica B vol 385-386 pp 444ndash446 2006
[10] O Kahn S J Miller and F Palacio Eds Magnetic MolecularMaterials vol 198 of NATO ASI Series E Plenum New YorkNY USA 1991
[11] S Juskzyk C Johanssont M Hansont A Ratusmas and GMakckill ldquoFerromagnetism of the Me
3[Fe(CN)
6]sdotH2o com-
pounds where Me = Ni and Cordquo Journal of Physics CondensedMatter vol 6 pp 5697ndash5765 1994
[12] J S Miller and A J Epstein ldquoOrganic and organometallicmolecular magnetic materials-designer magnetsrdquo AngewandteChemie International Edition in English vol 33 no 4 pp 385ndash415 1994
[13] O Kahn Molecular Magnetism Wiley-VCH New York NYUSA 1993
[14] W E Buschmann and J S Miller ldquoMagnetic ordering and spin-glass behavior in first-row transition metal hexacyanoman-ganate(IV) Prussian Blue analoguesrdquo Inorganic Chemistry vol39 no 11 pp 2411ndash2421 2000
[15] Y He Y-D Dai H-B Huang J Lin and Y-F Hsia ldquoSpin-glass state and ferromagnetic order in Cu(II)-Fe(III) cyanidesrdquoChinese Physics vol 13 no 5 pp 746ndash749 2004
[16] H Huang L Wei Y He X Li and F Liang ldquoFerromagneticorder and spin-glass behavior in multi-metallic compoundNi1125
Co0375
[Fe(CN)6] sdot 68H
2Ordquo Current Applied Physics vol
9 no 5 pp 1160ndash1164 2009[17] S-I Ohkoshi S Yorozu O Sato T Iyoda A Fujishima and
K Hashimoto ldquoPhotoinduced magnetic pole inversion in aferro-ferrimagnet (FeII040MnII
060)15CrIII(CN)6rdquo Applied Physics
Letters vol 70 no 8 pp 1040ndash1042 1997[18] D Sherrington and S Kirkpatrick ldquoSolvable model of a spin-
glassrdquo Physical Review Letters vol 35 no 26 pp 1792ndash17961975
[19] M Gabay and G Toulouse ldquoCoexistence of spin-glass andferromagnetic orderingsrdquo Physical Review Letters vol 47 no 3pp 201ndash204 1981
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Journal of Spectroscopy 3
0 5 10 15 20 25 30 35 40 45 50
0000
minus0005
minus0035
minus0030
minus0025
minus0020
minus0015
minus0010
T (K)
dMdT
Tc = 85K
Figure 4 119889119872119889119879 versus 119879 for the compound
0 50 100 150 200 250 300
00
05
10
15
20
25
T (K)
120594M
(cm3middotm
olminus1)
Figure 5 120594119898versus 119879 for the compound
0 50 100 150 200 250 300
0
10
20
30
40
50
Data
120594Mminus1
(cmminus3middotm
ol)
120579 = minus932K
T (K)
Linear fit
Figure 6 120594119898
minus1 versus 119879 for the compound
0 50 100 150 200 250 3004
6
8
10
12
14
16
120594MT
(cm3middotm
olminus1middotK
)
120594MT
T (K)
Figure 7 120594119898119879 versus 119879 for the compound
and the Curie-Weiss temperature (120579) are estimated by a linearfitting of 1120594 = (119879 minus 120579)119862 at the linear region [8ndash10] Fittingyielded that the Curie constant 119862 = 1520 cm3sdotKsdotmolminus1 andparamagnetic Curie temperature 120579 = minus932K The values of119879
119862 120579 and 119862 are different from those values for ferrimagnet
Ni15[Fe(CN)
6]sdotxH2O [10] andMn
3[Fe (CN)
6]2sdot15H2O (119879119862=
9K) [11]A curve of 120594
119898119879 versus 119879 is shown in Figure 7 and
the 120594119898119879 value at room temperature is 57 cm3sdotKsdotmolminus1
Upon lowering the temperature 120594119898119879 value sharply increases
after 15 K with a further decrease of the temperature The120594
119898119879 shows a sharp maximum value of 353 cm3sdotKsdotmolminus1
at 9 K and then finally decreases more rapidly on furthercooling For a ferromagnetic compound 120594
119898119879 versus 119879 curve
reaches a minimum before rising around magnetic orderingtemperature [12ndash14]
A curve of 120583eff versus 119879 is shown in Figure 8The effectivemoment 120583eff first slowly decreases to reach a minimum of647 120583B at 23 K and then sharply increases to reachmaximumof 1683 120583B at 9 K and final decrease at lower tempera-ture indicating antiferromagnetic interaction between para-magnetic centers [15ndash17] Magnetic transition temperaturewas estimated from minimum of 119889120583eff119889119879 versus 119879 curvewhich corresponds to the steepest increase of magnetizationwith decreasing temperature (as shown in Figure 6 insertplot of 119889120583eff119889119879 versus 119879) The compound undergoes aparamagnetic to ferroferrimagnetic type phase transitionat 95 K which could be attributed to an intermolecularantiferromagnetic interaction andor a zero-field splitting(ZFS) effect This kind of behaviour is a characteristic of aferromagnet [18 19]
33 Zero-Field-Cooled (ZFC) and Field-Cooled (FC) Mag-netization Figure 9 shows the curves of zero-field-cooled(ZFC) and field-cooled (FC)magnetization of the compoundat different field 119867 = 20 100 250 and 500Oe Thevalues of 119872 increase and exhibit weak irreversibility in
4 Journal of Spectroscopy
0 50 100 150 200 250 300
6
8
10
12
14
16
18
0 5 10 15 20 25 30 35 40 45 50
0
1
2
Data
T (K)
T (K)
d120583
effdT
Tc = 95K
minus1
minus2
minus3
120583ef
f(120583
120573)
Figure 8 120583eff versus 119879 for the compound (insert plot of 119889120583eff119889119879versus 119879)
2 4 6 8 10 12 14 16 18 20
0
500
1000
1500
2000
2500
3000
3500
4000
20Oe100Oe
250Oe500Oe
20Oe100Oe
250Oe500Oe
MFC
MZFC
M(c
m3middotGmiddotm
olminus1)
T (K)
Figure 9 ZFC and FC magnetization curves with different field
the field-cooled (FC) magnetization curves below 119879119862= 12K
There is a clear bifurcation phenomenon of the field-cooled(119872FC) and zero-field-cooled (119872ZFC) magnetization curves119879irr is a bifurcation temperature point of which FC and ZFCmagnetization curves separate out In addition the behaviorthat119872ZFC exhibits a maximum below 119879irr is attributed to thecooperative freezing of spin glass (as shown in Figure 10)The irreversible behavior of119872 and shift of bifurcation pointto lower temperature with increasing 119867 are characteristicfor spin glasses [10 11] It may be reasonable that thesemetal ions FeIII NiII and MnII through cyanide-bridgedligand have the coexistence of different valence states or spinstates the presence of inhomogeneity and inherent structuraldisorder which propagate possibly the ferromagnetic andantiferromagnetic exchange interaction via bridging cyanide
0 100 200 300 400 500 600
5
6
7
8
9
10
11
12
13
14
TirrTmax
T(K
)
H (Oe)
Linear fit
Figure 10 119879irr and 119879max versus119867 for the compound
2 4 6 8 10 12 14 16
0
1
2
3
4
5
10Hz32Hz100Hz
320Hz1000Hz
120594M
(cm3middotm
olminus1)
T (K)
120594998400M
120594998400M
Figure 11 1205941015840(119879) and 12059410158401015840(119879) curves of AC magnetic susceptibility ofthe compound with different frequencies
and there exist a structural disorder and a certain contentof crystallization water which lead to the weak spin-orbitcoupling The spin-glass property is due to magnetic domainkinetics under different cooling conditions and the presenceof available vacant sites in the lattice for the water molecules
34 AC Magnetic Susceptibility It was also confirmed thatthere exists a spin-glass behavior in the compound throughAC magnetization curves The AC magnetic susceptibilityof the compound was measured at 4Oe AC amplitude withzero-applied DC field when varying the frequencies (119891) from10 to 1000Hz as shown in Figure 11 The temperature depen-dence of zero-static field AC magnetic susceptibilities shows
Journal of Spectroscopy 5
10 15 20 25 30
7773
7776
7779
7782
7785
7788
7791
Data
log(w)
Tf
(K)
Linear fit
Figure 12 The log(119908) dependence of the 119879119891
that the in-phase component (1205941015840) has a maximum at about77 K for frequencies of 10 32 100 320 and 997Hz and that asignificant out-of-phase component (12059410158401015840) appears confirm-ing the long-range ferromagnetic ordering On decreasingtemperature the in-phase signals 1205941015840 increase abruptly ataround 12K reach the maximum at about 77 K and thendecrease slowlyThe out-of-phase signals 12059410158401015840 increase steadilyto the maximum around 8K and then decrease slowly asshown in Figure 11 The fact that the 1205941015840 (119879) clearly shows afrequency dependence is typically assigned to spin glasses [1213] The freezing temperature (119879
119891) 119879119891= 77K is defined by
the maximum in the 119909AC(119879) plot at low frequency It under-goes a paramagnetic to ferromagnetic transition at around77 K In fact the temperature value of the maximum of 120594 at agiven frequency (119899) corresponds to the blocking temperature(119879119873= 119879max) whereby it is assumed that the switching
of the oscillating AC field matches the relaxation rate ofthe magnetization
Proportional relationship between freezing temperature119879
119891and logarithm of frequency in spin-glass system can be
described by quantifying the frequency dependence throughthe ratio 119888 which can be written as 119888 = Δ119879
119891119879
119891Δ log119908
119879
119891(119908) versus log(119908) is shown in Figure 12 The value of
freezing temperature of zero frequency is 119879119892= 776K by
extrapolation method and the value of 119888 obtained for thecompound is 00011 which fall within the range typical for theconventional spin-glass system (10minus2-10minus3) Surprisingly boththe in-phase and out-of-phase signals (1205941015840 and 12059410158401015840) go througha maximum with strong frequency dependence Both in thereal and in the imaginary components the peaks shift tolower temperatures with decreasing frequencies Howeverthe intensities of the peaks behave differently While theintensity of the peaks for the real component increases withdecreasing frequencies in the imaginary component theintensity of the peaks decreases with decreasing frequencies
0 10 20 30 40 50
00
05
10
15
20
25
30
35
40
H (kOe)
minus05
M(120583
120573)
Figure 13 Field-dependent magnetization curves
0 2000 40000
2000
4000
6000
8000
minus4000 minus2000minus2000
minus4000
minus6000
minus8000
M(e
mu g
minus1)
H (Oe)
Figure 14 The hysteresis loop for the compound
This behaviour of 12059410158401015840 and 12059410158401015840 is typical of a spin-glassstate [16ndash19]
35 Field-Dependent Magnetization and Hysteresis BehaviorIn order to further understand the nature of magnetic order-ing the ferromagnetism behavior is characterized by themeasurements of field-dependent magnetization as shownin Figures 11 and 13 The observed 119872
119904value is 385 120583B
at 50 kOe but the compound does not reach full satura-tion and this behavior is likely to be related to the spin-glass behavior as well as the amount of spin and type ofcoupling in the compounds Ni
15[Fe(CN)
6]sdotxH2O [18] and
Mn3[Fe(CN)
6]2sdot15H2O [10]
Ferromagnetism in thecompoundNi025
Mn125
[Fe(CN)6]sdot
61H2O is also supported by hysteresis loop curves measured
at 4 K as shown in Figure 14 The coercive field (119867119888) was
032 kOe which was smaller than that of the compoundNi15[Fe(CN)
6]sdotxH2O (119867119888= 25 KOe44 K) [12] The rema-
nent magnetization (119872119903) with 032 120583B for the compound It is
also obtained by the hysteresis loop curvesTherefore synthesis ideas of molecular alloy magnet can
be regarded as a synthesis method to expand a new typeof magnetic functional materials whose magnetic properties
6 Journal of Spectroscopy
can be tuned and controlled by changing the composition ofdifferent transition metal cations [15 17ndash19]
4 Conclusion
We have reported a detailed investigation of magneticproperties of multimetallic Prussian blue compoundsNi025
Mn125
[Fe(CN)6]sdot61H
2O The temperature-depend-
ent magnetic susceptibilities show the magnetism tran-sition for the compound at 85 K The Curie constant(119862 = 1520 cm3sdotKsdotmolminus1) and the Curie-Weiss temperature(120579 = minus932K) are obtained through a linear fitting of1120594 = (119879 minus 120579)119862 at the linear region [8ndash10]
The observed values of coercive field (119867119888) and remanent
magnetization (119872119903) for the compound are 032 KOe and
036 120583119861 Moreover there exists a spin-glass behaviour in the
compound according to study of zero-field-cooled (ZFC) andfield-cooled (FC) magnetization curves and AC magnetiza-tion curves which exhibits freezing temperature119879
119892= 776K
below magnetic transition 119879119888= 85K Such a glass behavior
is termed ldquoreentrantrdquo spin glass It was also confirmed by thebehaviour of 12059410158401015840 and 12059410158401015840 which go through a maximum withstrong frequency dependence
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
This work was financially supported by the National NaturalScience Foundation of China (nos 11164002 and 11364004)and Innovation Project of Guangxi Graduate Educationunder Grant no 0991092
References
[1] J M Manriquez G T Yee R S Mclean A J Epsteinand J S Miller ldquoA room-temperature molecularorganic-basedmagnetrdquo Science vol 252 no 5011 pp 1415ndash1417 1991
[2] S Ferlay T Mallah R Ouahes P Veillet and M Verdaguer ldquoAroom-temperature organometallic magnet based on Prussianbluerdquo Nature vol 378 no 6558 pp 701ndash703 1995
[3] O Sato T Iyoda A Fujishima and K Hashimoto ldquoElec-trochemical tunable magnetic phase transition in a high-Tcchromium cyanide thin filmrdquo Science vol 271 no 5245 pp 49ndash51 1996
[4] M Giorgetti ldquoA review on the structural studies of batteriesand host materials by X-ray absorption spectroscopyrdquo ISRNMaterials Science vol 2013 Article ID 938625 22 pages 2013
[5] S-I Ohkoshi T Iyoda A Fujishima and K HashimotoldquoMagnetic properties of mixed ferro-ferrimagnets composed ofPrussian blue analogsrdquoPhysical ReviewBCondensedMatter andMaterials Physics vol 56 no 18 pp 11642ndash11652 1997
[6] S Ohkoshi O Sato T Iyoda A Fujishima and K HashimotoldquoTuning of superexchange couplings in amolecule-based ferro-ferrimagnet (Ni119868119868
119909Mn1198681198681minus119909
) 15 [Cr119868119868119868 (CN)6]rdquo Inorganic Chem-
istry vol 36 pp 268ndash269 1997
[7] S-I Ohkoshi Y Abe A Fujishima and K Hashimoto ldquoDesignand preparation of a novelmagnet exhibiting two compensationtemperatures based on molecular field theoryrdquo Physical ReviewLetters vol 82 no 6 pp 1285ndash1288 1999
[8] A Kumar and S M Yusuf ldquoMagnetic properties of multi-metalPrussian Blue analogue Co
075Ni075
[Fe(CN)6]sdot68H
2Ordquo Physica
B Condensed Matter vol 362 no 1ndash4 pp 278ndash285 2005[9] A Kumar S M Yusuf and L Keller ldquoNeutron diffraction study
of molecular magnetic compound Ni1125
Co0375
[Fe(CN)6]sdot
64H2Ordquo Physica B vol 385-386 pp 444ndash446 2006
[10] O Kahn S J Miller and F Palacio Eds Magnetic MolecularMaterials vol 198 of NATO ASI Series E Plenum New YorkNY USA 1991
[11] S Juskzyk C Johanssont M Hansont A Ratusmas and GMakckill ldquoFerromagnetism of the Me
3[Fe(CN)
6]sdotH2o com-
pounds where Me = Ni and Cordquo Journal of Physics CondensedMatter vol 6 pp 5697ndash5765 1994
[12] J S Miller and A J Epstein ldquoOrganic and organometallicmolecular magnetic materials-designer magnetsrdquo AngewandteChemie International Edition in English vol 33 no 4 pp 385ndash415 1994
[13] O Kahn Molecular Magnetism Wiley-VCH New York NYUSA 1993
[14] W E Buschmann and J S Miller ldquoMagnetic ordering and spin-glass behavior in first-row transition metal hexacyanoman-ganate(IV) Prussian Blue analoguesrdquo Inorganic Chemistry vol39 no 11 pp 2411ndash2421 2000
[15] Y He Y-D Dai H-B Huang J Lin and Y-F Hsia ldquoSpin-glass state and ferromagnetic order in Cu(II)-Fe(III) cyanidesrdquoChinese Physics vol 13 no 5 pp 746ndash749 2004
[16] H Huang L Wei Y He X Li and F Liang ldquoFerromagneticorder and spin-glass behavior in multi-metallic compoundNi1125
Co0375
[Fe(CN)6] sdot 68H
2Ordquo Current Applied Physics vol
9 no 5 pp 1160ndash1164 2009[17] S-I Ohkoshi S Yorozu O Sato T Iyoda A Fujishima and
K Hashimoto ldquoPhotoinduced magnetic pole inversion in aferro-ferrimagnet (FeII040MnII
060)15CrIII(CN)6rdquo Applied Physics
Letters vol 70 no 8 pp 1040ndash1042 1997[18] D Sherrington and S Kirkpatrick ldquoSolvable model of a spin-
glassrdquo Physical Review Letters vol 35 no 26 pp 1792ndash17961975
[19] M Gabay and G Toulouse ldquoCoexistence of spin-glass andferromagnetic orderingsrdquo Physical Review Letters vol 47 no 3pp 201ndash204 1981
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
4 Journal of Spectroscopy
0 50 100 150 200 250 300
6
8
10
12
14
16
18
0 5 10 15 20 25 30 35 40 45 50
0
1
2
Data
T (K)
T (K)
d120583
effdT
Tc = 95K
minus1
minus2
minus3
120583ef
f(120583
120573)
Figure 8 120583eff versus 119879 for the compound (insert plot of 119889120583eff119889119879versus 119879)
2 4 6 8 10 12 14 16 18 20
0
500
1000
1500
2000
2500
3000
3500
4000
20Oe100Oe
250Oe500Oe
20Oe100Oe
250Oe500Oe
MFC
MZFC
M(c
m3middotGmiddotm
olminus1)
T (K)
Figure 9 ZFC and FC magnetization curves with different field
the field-cooled (FC) magnetization curves below 119879119862= 12K
There is a clear bifurcation phenomenon of the field-cooled(119872FC) and zero-field-cooled (119872ZFC) magnetization curves119879irr is a bifurcation temperature point of which FC and ZFCmagnetization curves separate out In addition the behaviorthat119872ZFC exhibits a maximum below 119879irr is attributed to thecooperative freezing of spin glass (as shown in Figure 10)The irreversible behavior of119872 and shift of bifurcation pointto lower temperature with increasing 119867 are characteristicfor spin glasses [10 11] It may be reasonable that thesemetal ions FeIII NiII and MnII through cyanide-bridgedligand have the coexistence of different valence states or spinstates the presence of inhomogeneity and inherent structuraldisorder which propagate possibly the ferromagnetic andantiferromagnetic exchange interaction via bridging cyanide
0 100 200 300 400 500 600
5
6
7
8
9
10
11
12
13
14
TirrTmax
T(K
)
H (Oe)
Linear fit
Figure 10 119879irr and 119879max versus119867 for the compound
2 4 6 8 10 12 14 16
0
1
2
3
4
5
10Hz32Hz100Hz
320Hz1000Hz
120594M
(cm3middotm
olminus1)
T (K)
120594998400M
120594998400M
Figure 11 1205941015840(119879) and 12059410158401015840(119879) curves of AC magnetic susceptibility ofthe compound with different frequencies
and there exist a structural disorder and a certain contentof crystallization water which lead to the weak spin-orbitcoupling The spin-glass property is due to magnetic domainkinetics under different cooling conditions and the presenceof available vacant sites in the lattice for the water molecules
34 AC Magnetic Susceptibility It was also confirmed thatthere exists a spin-glass behavior in the compound throughAC magnetization curves The AC magnetic susceptibilityof the compound was measured at 4Oe AC amplitude withzero-applied DC field when varying the frequencies (119891) from10 to 1000Hz as shown in Figure 11 The temperature depen-dence of zero-static field AC magnetic susceptibilities shows
Journal of Spectroscopy 5
10 15 20 25 30
7773
7776
7779
7782
7785
7788
7791
Data
log(w)
Tf
(K)
Linear fit
Figure 12 The log(119908) dependence of the 119879119891
that the in-phase component (1205941015840) has a maximum at about77 K for frequencies of 10 32 100 320 and 997Hz and that asignificant out-of-phase component (12059410158401015840) appears confirm-ing the long-range ferromagnetic ordering On decreasingtemperature the in-phase signals 1205941015840 increase abruptly ataround 12K reach the maximum at about 77 K and thendecrease slowlyThe out-of-phase signals 12059410158401015840 increase steadilyto the maximum around 8K and then decrease slowly asshown in Figure 11 The fact that the 1205941015840 (119879) clearly shows afrequency dependence is typically assigned to spin glasses [1213] The freezing temperature (119879
119891) 119879119891= 77K is defined by
the maximum in the 119909AC(119879) plot at low frequency It under-goes a paramagnetic to ferromagnetic transition at around77 K In fact the temperature value of the maximum of 120594 at agiven frequency (119899) corresponds to the blocking temperature(119879119873= 119879max) whereby it is assumed that the switching
of the oscillating AC field matches the relaxation rate ofthe magnetization
Proportional relationship between freezing temperature119879
119891and logarithm of frequency in spin-glass system can be
described by quantifying the frequency dependence throughthe ratio 119888 which can be written as 119888 = Δ119879
119891119879
119891Δ log119908
119879
119891(119908) versus log(119908) is shown in Figure 12 The value of
freezing temperature of zero frequency is 119879119892= 776K by
extrapolation method and the value of 119888 obtained for thecompound is 00011 which fall within the range typical for theconventional spin-glass system (10minus2-10minus3) Surprisingly boththe in-phase and out-of-phase signals (1205941015840 and 12059410158401015840) go througha maximum with strong frequency dependence Both in thereal and in the imaginary components the peaks shift tolower temperatures with decreasing frequencies Howeverthe intensities of the peaks behave differently While theintensity of the peaks for the real component increases withdecreasing frequencies in the imaginary component theintensity of the peaks decreases with decreasing frequencies
0 10 20 30 40 50
00
05
10
15
20
25
30
35
40
H (kOe)
minus05
M(120583
120573)
Figure 13 Field-dependent magnetization curves
0 2000 40000
2000
4000
6000
8000
minus4000 minus2000minus2000
minus4000
minus6000
minus8000
M(e
mu g
minus1)
H (Oe)
Figure 14 The hysteresis loop for the compound
This behaviour of 12059410158401015840 and 12059410158401015840 is typical of a spin-glassstate [16ndash19]
35 Field-Dependent Magnetization and Hysteresis BehaviorIn order to further understand the nature of magnetic order-ing the ferromagnetism behavior is characterized by themeasurements of field-dependent magnetization as shownin Figures 11 and 13 The observed 119872
119904value is 385 120583B
at 50 kOe but the compound does not reach full satura-tion and this behavior is likely to be related to the spin-glass behavior as well as the amount of spin and type ofcoupling in the compounds Ni
15[Fe(CN)
6]sdotxH2O [18] and
Mn3[Fe(CN)
6]2sdot15H2O [10]
Ferromagnetism in thecompoundNi025
Mn125
[Fe(CN)6]sdot
61H2O is also supported by hysteresis loop curves measured
at 4 K as shown in Figure 14 The coercive field (119867119888) was
032 kOe which was smaller than that of the compoundNi15[Fe(CN)
6]sdotxH2O (119867119888= 25 KOe44 K) [12] The rema-
nent magnetization (119872119903) with 032 120583B for the compound It is
also obtained by the hysteresis loop curvesTherefore synthesis ideas of molecular alloy magnet can
be regarded as a synthesis method to expand a new typeof magnetic functional materials whose magnetic properties
6 Journal of Spectroscopy
can be tuned and controlled by changing the composition ofdifferent transition metal cations [15 17ndash19]
4 Conclusion
We have reported a detailed investigation of magneticproperties of multimetallic Prussian blue compoundsNi025
Mn125
[Fe(CN)6]sdot61H
2O The temperature-depend-
ent magnetic susceptibilities show the magnetism tran-sition for the compound at 85 K The Curie constant(119862 = 1520 cm3sdotKsdotmolminus1) and the Curie-Weiss temperature(120579 = minus932K) are obtained through a linear fitting of1120594 = (119879 minus 120579)119862 at the linear region [8ndash10]
The observed values of coercive field (119867119888) and remanent
magnetization (119872119903) for the compound are 032 KOe and
036 120583119861 Moreover there exists a spin-glass behaviour in the
compound according to study of zero-field-cooled (ZFC) andfield-cooled (FC) magnetization curves and AC magnetiza-tion curves which exhibits freezing temperature119879
119892= 776K
below magnetic transition 119879119888= 85K Such a glass behavior
is termed ldquoreentrantrdquo spin glass It was also confirmed by thebehaviour of 12059410158401015840 and 12059410158401015840 which go through a maximum withstrong frequency dependence
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
This work was financially supported by the National NaturalScience Foundation of China (nos 11164002 and 11364004)and Innovation Project of Guangxi Graduate Educationunder Grant no 0991092
References
[1] J M Manriquez G T Yee R S Mclean A J Epsteinand J S Miller ldquoA room-temperature molecularorganic-basedmagnetrdquo Science vol 252 no 5011 pp 1415ndash1417 1991
[2] S Ferlay T Mallah R Ouahes P Veillet and M Verdaguer ldquoAroom-temperature organometallic magnet based on Prussianbluerdquo Nature vol 378 no 6558 pp 701ndash703 1995
[3] O Sato T Iyoda A Fujishima and K Hashimoto ldquoElec-trochemical tunable magnetic phase transition in a high-Tcchromium cyanide thin filmrdquo Science vol 271 no 5245 pp 49ndash51 1996
[4] M Giorgetti ldquoA review on the structural studies of batteriesand host materials by X-ray absorption spectroscopyrdquo ISRNMaterials Science vol 2013 Article ID 938625 22 pages 2013
[5] S-I Ohkoshi T Iyoda A Fujishima and K HashimotoldquoMagnetic properties of mixed ferro-ferrimagnets composed ofPrussian blue analogsrdquoPhysical ReviewBCondensedMatter andMaterials Physics vol 56 no 18 pp 11642ndash11652 1997
[6] S Ohkoshi O Sato T Iyoda A Fujishima and K HashimotoldquoTuning of superexchange couplings in amolecule-based ferro-ferrimagnet (Ni119868119868
119909Mn1198681198681minus119909
) 15 [Cr119868119868119868 (CN)6]rdquo Inorganic Chem-
istry vol 36 pp 268ndash269 1997
[7] S-I Ohkoshi Y Abe A Fujishima and K Hashimoto ldquoDesignand preparation of a novelmagnet exhibiting two compensationtemperatures based on molecular field theoryrdquo Physical ReviewLetters vol 82 no 6 pp 1285ndash1288 1999
[8] A Kumar and S M Yusuf ldquoMagnetic properties of multi-metalPrussian Blue analogue Co
075Ni075
[Fe(CN)6]sdot68H
2Ordquo Physica
B Condensed Matter vol 362 no 1ndash4 pp 278ndash285 2005[9] A Kumar S M Yusuf and L Keller ldquoNeutron diffraction study
of molecular magnetic compound Ni1125
Co0375
[Fe(CN)6]sdot
64H2Ordquo Physica B vol 385-386 pp 444ndash446 2006
[10] O Kahn S J Miller and F Palacio Eds Magnetic MolecularMaterials vol 198 of NATO ASI Series E Plenum New YorkNY USA 1991
[11] S Juskzyk C Johanssont M Hansont A Ratusmas and GMakckill ldquoFerromagnetism of the Me
3[Fe(CN)
6]sdotH2o com-
pounds where Me = Ni and Cordquo Journal of Physics CondensedMatter vol 6 pp 5697ndash5765 1994
[12] J S Miller and A J Epstein ldquoOrganic and organometallicmolecular magnetic materials-designer magnetsrdquo AngewandteChemie International Edition in English vol 33 no 4 pp 385ndash415 1994
[13] O Kahn Molecular Magnetism Wiley-VCH New York NYUSA 1993
[14] W E Buschmann and J S Miller ldquoMagnetic ordering and spin-glass behavior in first-row transition metal hexacyanoman-ganate(IV) Prussian Blue analoguesrdquo Inorganic Chemistry vol39 no 11 pp 2411ndash2421 2000
[15] Y He Y-D Dai H-B Huang J Lin and Y-F Hsia ldquoSpin-glass state and ferromagnetic order in Cu(II)-Fe(III) cyanidesrdquoChinese Physics vol 13 no 5 pp 746ndash749 2004
[16] H Huang L Wei Y He X Li and F Liang ldquoFerromagneticorder and spin-glass behavior in multi-metallic compoundNi1125
Co0375
[Fe(CN)6] sdot 68H
2Ordquo Current Applied Physics vol
9 no 5 pp 1160ndash1164 2009[17] S-I Ohkoshi S Yorozu O Sato T Iyoda A Fujishima and
K Hashimoto ldquoPhotoinduced magnetic pole inversion in aferro-ferrimagnet (FeII040MnII
060)15CrIII(CN)6rdquo Applied Physics
Letters vol 70 no 8 pp 1040ndash1042 1997[18] D Sherrington and S Kirkpatrick ldquoSolvable model of a spin-
glassrdquo Physical Review Letters vol 35 no 26 pp 1792ndash17961975
[19] M Gabay and G Toulouse ldquoCoexistence of spin-glass andferromagnetic orderingsrdquo Physical Review Letters vol 47 no 3pp 201ndash204 1981
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Journal of Spectroscopy 5
10 15 20 25 30
7773
7776
7779
7782
7785
7788
7791
Data
log(w)
Tf
(K)
Linear fit
Figure 12 The log(119908) dependence of the 119879119891
that the in-phase component (1205941015840) has a maximum at about77 K for frequencies of 10 32 100 320 and 997Hz and that asignificant out-of-phase component (12059410158401015840) appears confirm-ing the long-range ferromagnetic ordering On decreasingtemperature the in-phase signals 1205941015840 increase abruptly ataround 12K reach the maximum at about 77 K and thendecrease slowlyThe out-of-phase signals 12059410158401015840 increase steadilyto the maximum around 8K and then decrease slowly asshown in Figure 11 The fact that the 1205941015840 (119879) clearly shows afrequency dependence is typically assigned to spin glasses [1213] The freezing temperature (119879
119891) 119879119891= 77K is defined by
the maximum in the 119909AC(119879) plot at low frequency It under-goes a paramagnetic to ferromagnetic transition at around77 K In fact the temperature value of the maximum of 120594 at agiven frequency (119899) corresponds to the blocking temperature(119879119873= 119879max) whereby it is assumed that the switching
of the oscillating AC field matches the relaxation rate ofthe magnetization
Proportional relationship between freezing temperature119879
119891and logarithm of frequency in spin-glass system can be
described by quantifying the frequency dependence throughthe ratio 119888 which can be written as 119888 = Δ119879
119891119879
119891Δ log119908
119879
119891(119908) versus log(119908) is shown in Figure 12 The value of
freezing temperature of zero frequency is 119879119892= 776K by
extrapolation method and the value of 119888 obtained for thecompound is 00011 which fall within the range typical for theconventional spin-glass system (10minus2-10minus3) Surprisingly boththe in-phase and out-of-phase signals (1205941015840 and 12059410158401015840) go througha maximum with strong frequency dependence Both in thereal and in the imaginary components the peaks shift tolower temperatures with decreasing frequencies Howeverthe intensities of the peaks behave differently While theintensity of the peaks for the real component increases withdecreasing frequencies in the imaginary component theintensity of the peaks decreases with decreasing frequencies
0 10 20 30 40 50
00
05
10
15
20
25
30
35
40
H (kOe)
minus05
M(120583
120573)
Figure 13 Field-dependent magnetization curves
0 2000 40000
2000
4000
6000
8000
minus4000 minus2000minus2000
minus4000
minus6000
minus8000
M(e
mu g
minus1)
H (Oe)
Figure 14 The hysteresis loop for the compound
This behaviour of 12059410158401015840 and 12059410158401015840 is typical of a spin-glassstate [16ndash19]
35 Field-Dependent Magnetization and Hysteresis BehaviorIn order to further understand the nature of magnetic order-ing the ferromagnetism behavior is characterized by themeasurements of field-dependent magnetization as shownin Figures 11 and 13 The observed 119872
119904value is 385 120583B
at 50 kOe but the compound does not reach full satura-tion and this behavior is likely to be related to the spin-glass behavior as well as the amount of spin and type ofcoupling in the compounds Ni
15[Fe(CN)
6]sdotxH2O [18] and
Mn3[Fe(CN)
6]2sdot15H2O [10]
Ferromagnetism in thecompoundNi025
Mn125
[Fe(CN)6]sdot
61H2O is also supported by hysteresis loop curves measured
at 4 K as shown in Figure 14 The coercive field (119867119888) was
032 kOe which was smaller than that of the compoundNi15[Fe(CN)
6]sdotxH2O (119867119888= 25 KOe44 K) [12] The rema-
nent magnetization (119872119903) with 032 120583B for the compound It is
also obtained by the hysteresis loop curvesTherefore synthesis ideas of molecular alloy magnet can
be regarded as a synthesis method to expand a new typeof magnetic functional materials whose magnetic properties
6 Journal of Spectroscopy
can be tuned and controlled by changing the composition ofdifferent transition metal cations [15 17ndash19]
4 Conclusion
We have reported a detailed investigation of magneticproperties of multimetallic Prussian blue compoundsNi025
Mn125
[Fe(CN)6]sdot61H
2O The temperature-depend-
ent magnetic susceptibilities show the magnetism tran-sition for the compound at 85 K The Curie constant(119862 = 1520 cm3sdotKsdotmolminus1) and the Curie-Weiss temperature(120579 = minus932K) are obtained through a linear fitting of1120594 = (119879 minus 120579)119862 at the linear region [8ndash10]
The observed values of coercive field (119867119888) and remanent
magnetization (119872119903) for the compound are 032 KOe and
036 120583119861 Moreover there exists a spin-glass behaviour in the
compound according to study of zero-field-cooled (ZFC) andfield-cooled (FC) magnetization curves and AC magnetiza-tion curves which exhibits freezing temperature119879
119892= 776K
below magnetic transition 119879119888= 85K Such a glass behavior
is termed ldquoreentrantrdquo spin glass It was also confirmed by thebehaviour of 12059410158401015840 and 12059410158401015840 which go through a maximum withstrong frequency dependence
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
This work was financially supported by the National NaturalScience Foundation of China (nos 11164002 and 11364004)and Innovation Project of Guangxi Graduate Educationunder Grant no 0991092
References
[1] J M Manriquez G T Yee R S Mclean A J Epsteinand J S Miller ldquoA room-temperature molecularorganic-basedmagnetrdquo Science vol 252 no 5011 pp 1415ndash1417 1991
[2] S Ferlay T Mallah R Ouahes P Veillet and M Verdaguer ldquoAroom-temperature organometallic magnet based on Prussianbluerdquo Nature vol 378 no 6558 pp 701ndash703 1995
[3] O Sato T Iyoda A Fujishima and K Hashimoto ldquoElec-trochemical tunable magnetic phase transition in a high-Tcchromium cyanide thin filmrdquo Science vol 271 no 5245 pp 49ndash51 1996
[4] M Giorgetti ldquoA review on the structural studies of batteriesand host materials by X-ray absorption spectroscopyrdquo ISRNMaterials Science vol 2013 Article ID 938625 22 pages 2013
[5] S-I Ohkoshi T Iyoda A Fujishima and K HashimotoldquoMagnetic properties of mixed ferro-ferrimagnets composed ofPrussian blue analogsrdquoPhysical ReviewBCondensedMatter andMaterials Physics vol 56 no 18 pp 11642ndash11652 1997
[6] S Ohkoshi O Sato T Iyoda A Fujishima and K HashimotoldquoTuning of superexchange couplings in amolecule-based ferro-ferrimagnet (Ni119868119868
119909Mn1198681198681minus119909
) 15 [Cr119868119868119868 (CN)6]rdquo Inorganic Chem-
istry vol 36 pp 268ndash269 1997
[7] S-I Ohkoshi Y Abe A Fujishima and K Hashimoto ldquoDesignand preparation of a novelmagnet exhibiting two compensationtemperatures based on molecular field theoryrdquo Physical ReviewLetters vol 82 no 6 pp 1285ndash1288 1999
[8] A Kumar and S M Yusuf ldquoMagnetic properties of multi-metalPrussian Blue analogue Co
075Ni075
[Fe(CN)6]sdot68H
2Ordquo Physica
B Condensed Matter vol 362 no 1ndash4 pp 278ndash285 2005[9] A Kumar S M Yusuf and L Keller ldquoNeutron diffraction study
of molecular magnetic compound Ni1125
Co0375
[Fe(CN)6]sdot
64H2Ordquo Physica B vol 385-386 pp 444ndash446 2006
[10] O Kahn S J Miller and F Palacio Eds Magnetic MolecularMaterials vol 198 of NATO ASI Series E Plenum New YorkNY USA 1991
[11] S Juskzyk C Johanssont M Hansont A Ratusmas and GMakckill ldquoFerromagnetism of the Me
3[Fe(CN)
6]sdotH2o com-
pounds where Me = Ni and Cordquo Journal of Physics CondensedMatter vol 6 pp 5697ndash5765 1994
[12] J S Miller and A J Epstein ldquoOrganic and organometallicmolecular magnetic materials-designer magnetsrdquo AngewandteChemie International Edition in English vol 33 no 4 pp 385ndash415 1994
[13] O Kahn Molecular Magnetism Wiley-VCH New York NYUSA 1993
[14] W E Buschmann and J S Miller ldquoMagnetic ordering and spin-glass behavior in first-row transition metal hexacyanoman-ganate(IV) Prussian Blue analoguesrdquo Inorganic Chemistry vol39 no 11 pp 2411ndash2421 2000
[15] Y He Y-D Dai H-B Huang J Lin and Y-F Hsia ldquoSpin-glass state and ferromagnetic order in Cu(II)-Fe(III) cyanidesrdquoChinese Physics vol 13 no 5 pp 746ndash749 2004
[16] H Huang L Wei Y He X Li and F Liang ldquoFerromagneticorder and spin-glass behavior in multi-metallic compoundNi1125
Co0375
[Fe(CN)6] sdot 68H
2Ordquo Current Applied Physics vol
9 no 5 pp 1160ndash1164 2009[17] S-I Ohkoshi S Yorozu O Sato T Iyoda A Fujishima and
K Hashimoto ldquoPhotoinduced magnetic pole inversion in aferro-ferrimagnet (FeII040MnII
060)15CrIII(CN)6rdquo Applied Physics
Letters vol 70 no 8 pp 1040ndash1042 1997[18] D Sherrington and S Kirkpatrick ldquoSolvable model of a spin-
glassrdquo Physical Review Letters vol 35 no 26 pp 1792ndash17961975
[19] M Gabay and G Toulouse ldquoCoexistence of spin-glass andferromagnetic orderingsrdquo Physical Review Letters vol 47 no 3pp 201ndash204 1981
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
6 Journal of Spectroscopy
can be tuned and controlled by changing the composition ofdifferent transition metal cations [15 17ndash19]
4 Conclusion
We have reported a detailed investigation of magneticproperties of multimetallic Prussian blue compoundsNi025
Mn125
[Fe(CN)6]sdot61H
2O The temperature-depend-
ent magnetic susceptibilities show the magnetism tran-sition for the compound at 85 K The Curie constant(119862 = 1520 cm3sdotKsdotmolminus1) and the Curie-Weiss temperature(120579 = minus932K) are obtained through a linear fitting of1120594 = (119879 minus 120579)119862 at the linear region [8ndash10]
The observed values of coercive field (119867119888) and remanent
magnetization (119872119903) for the compound are 032 KOe and
036 120583119861 Moreover there exists a spin-glass behaviour in the
compound according to study of zero-field-cooled (ZFC) andfield-cooled (FC) magnetization curves and AC magnetiza-tion curves which exhibits freezing temperature119879
119892= 776K
below magnetic transition 119879119888= 85K Such a glass behavior
is termed ldquoreentrantrdquo spin glass It was also confirmed by thebehaviour of 12059410158401015840 and 12059410158401015840 which go through a maximum withstrong frequency dependence
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgments
This work was financially supported by the National NaturalScience Foundation of China (nos 11164002 and 11364004)and Innovation Project of Guangxi Graduate Educationunder Grant no 0991092
References
[1] J M Manriquez G T Yee R S Mclean A J Epsteinand J S Miller ldquoA room-temperature molecularorganic-basedmagnetrdquo Science vol 252 no 5011 pp 1415ndash1417 1991
[2] S Ferlay T Mallah R Ouahes P Veillet and M Verdaguer ldquoAroom-temperature organometallic magnet based on Prussianbluerdquo Nature vol 378 no 6558 pp 701ndash703 1995
[3] O Sato T Iyoda A Fujishima and K Hashimoto ldquoElec-trochemical tunable magnetic phase transition in a high-Tcchromium cyanide thin filmrdquo Science vol 271 no 5245 pp 49ndash51 1996
[4] M Giorgetti ldquoA review on the structural studies of batteriesand host materials by X-ray absorption spectroscopyrdquo ISRNMaterials Science vol 2013 Article ID 938625 22 pages 2013
[5] S-I Ohkoshi T Iyoda A Fujishima and K HashimotoldquoMagnetic properties of mixed ferro-ferrimagnets composed ofPrussian blue analogsrdquoPhysical ReviewBCondensedMatter andMaterials Physics vol 56 no 18 pp 11642ndash11652 1997
[6] S Ohkoshi O Sato T Iyoda A Fujishima and K HashimotoldquoTuning of superexchange couplings in amolecule-based ferro-ferrimagnet (Ni119868119868
119909Mn1198681198681minus119909
) 15 [Cr119868119868119868 (CN)6]rdquo Inorganic Chem-
istry vol 36 pp 268ndash269 1997
[7] S-I Ohkoshi Y Abe A Fujishima and K Hashimoto ldquoDesignand preparation of a novelmagnet exhibiting two compensationtemperatures based on molecular field theoryrdquo Physical ReviewLetters vol 82 no 6 pp 1285ndash1288 1999
[8] A Kumar and S M Yusuf ldquoMagnetic properties of multi-metalPrussian Blue analogue Co
075Ni075
[Fe(CN)6]sdot68H
2Ordquo Physica
B Condensed Matter vol 362 no 1ndash4 pp 278ndash285 2005[9] A Kumar S M Yusuf and L Keller ldquoNeutron diffraction study
of molecular magnetic compound Ni1125
Co0375
[Fe(CN)6]sdot
64H2Ordquo Physica B vol 385-386 pp 444ndash446 2006
[10] O Kahn S J Miller and F Palacio Eds Magnetic MolecularMaterials vol 198 of NATO ASI Series E Plenum New YorkNY USA 1991
[11] S Juskzyk C Johanssont M Hansont A Ratusmas and GMakckill ldquoFerromagnetism of the Me
3[Fe(CN)
6]sdotH2o com-
pounds where Me = Ni and Cordquo Journal of Physics CondensedMatter vol 6 pp 5697ndash5765 1994
[12] J S Miller and A J Epstein ldquoOrganic and organometallicmolecular magnetic materials-designer magnetsrdquo AngewandteChemie International Edition in English vol 33 no 4 pp 385ndash415 1994
[13] O Kahn Molecular Magnetism Wiley-VCH New York NYUSA 1993
[14] W E Buschmann and J S Miller ldquoMagnetic ordering and spin-glass behavior in first-row transition metal hexacyanoman-ganate(IV) Prussian Blue analoguesrdquo Inorganic Chemistry vol39 no 11 pp 2411ndash2421 2000
[15] Y He Y-D Dai H-B Huang J Lin and Y-F Hsia ldquoSpin-glass state and ferromagnetic order in Cu(II)-Fe(III) cyanidesrdquoChinese Physics vol 13 no 5 pp 746ndash749 2004
[16] H Huang L Wei Y He X Li and F Liang ldquoFerromagneticorder and spin-glass behavior in multi-metallic compoundNi1125
Co0375
[Fe(CN)6] sdot 68H
2Ordquo Current Applied Physics vol
9 no 5 pp 1160ndash1164 2009[17] S-I Ohkoshi S Yorozu O Sato T Iyoda A Fujishima and
K Hashimoto ldquoPhotoinduced magnetic pole inversion in aferro-ferrimagnet (FeII040MnII
060)15CrIII(CN)6rdquo Applied Physics
Letters vol 70 no 8 pp 1040ndash1042 1997[18] D Sherrington and S Kirkpatrick ldquoSolvable model of a spin-
glassrdquo Physical Review Letters vol 35 no 26 pp 1792ndash17961975
[19] M Gabay and G Toulouse ldquoCoexistence of spin-glass andferromagnetic orderingsrdquo Physical Review Letters vol 47 no 3pp 201ndash204 1981
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Inorganic ChemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
International Journal ofPhotoenergy
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Carbohydrate Chemistry
International Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Physical Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom
Analytical Methods in Chemistry
Journal of
Volume 2014
Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
SpectroscopyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Medicinal ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Chromatography Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Applied ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Theoretical ChemistryJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Spectroscopy
Analytical ChemistryInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Quantum Chemistry
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Organic Chemistry International
ElectrochemistryInternational Journal of
Hindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
CatalystsJournal of