Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach...
Transcript of Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach...
![Page 1: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/1.jpg)
Magnetyzm w półprzewodnikach
Tomasz DIETLInstitute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic and Spintronic ResearchInstitute of Theoretical Physics, Warsaw University
finansowanie: ERATO – JST; NANOSPIN -- EC project;SPINTRA – ESF; Humboldt Foundation, AdG ERC „FunDMS”
współpracownicy:
M. Sawicki et al. – WarszawaJ. Cibert et al. – GrenobleH. Ohno et al. – SendaiS. Kuroda et al. – TsukubaA. Bonanni et al. – LinzB. Gallagher et al. – NottinghamL. Molenkamp et al. – Wuerzburg
artyku łłłły przegl ąąąądowe, patrz arXiv; : J. Phys. C’07; JAP’08, JPSJ’08
![Page 2: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/2.jpg)
Spintronics -- materials aspectSpintronics -- materials aspect
Why to do not combine complementary resources of ferromagnets and semiconductors?
TopGaN
![Page 3: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/3.jpg)
Spintronics -- materials aspectSpintronics -- materials aspect
Why to do not combine complementary resources of ferromagnets and semiconductors?
� hybrid ferromagnetic-metal/semiconductor structures
TopGaN
• spin injection A. Hanbicki et al. (NRL) APL’03, Nature Phys. ‘07
• optical isolators H. Shimizu et al. (Tokyo) JJAP’04
• Stern-Gerlach aparatus J. Wróbel et al. (Warsaw) PRL’04
• .....
![Page 4: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/4.jpg)
Spintronics -- materials aspectSpintronics -- materials aspect
Why to do not combine complementary resources of ferromagnets and semiconductors?
TopGaN
� ferromagnetic semiconductors – multifunctional materials
![Page 5: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/5.jpg)
• Antiferromagnetic superexchange dominatesin magnetic insulators and semiconductors ���� no spontaneous magnetization
NiO, MnSe, EuTe, …
Making semiconductors ferromagnetic
Mn Se Mn
![Page 6: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/6.jpg)
• Antiferromagnetic superexchange dominatesin magnetic insulators and semiconductors ���� no spontaneous magnetization
NiO, MnSe, EuTe, …
• Exceptions-- ferrimagnets (two ions or two spin states co-exist)
NiO(Fe2O3), Mn4N, …
Making semiconductors ferromagnetic
Mn Se Mn
![Page 7: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/7.jpg)
• Antiferromagnetic superexchange dominatesin magnetic insulators and semiconductors ���� no spontaneous magnetization
NiO, MnSe, EuTe, …
• Exceptions-- ferrimagnets (two ions or two spin states co-exist)
NiO(Fe2O3), Mn4N, …
-- double exchange (two charge states co-exist)
LaMnO3 � La1-xSrxMnO3 (holes in d band)
Making semiconductors ferromagnetic
Mn+3 Mn+4
Mn Se Mn
![Page 8: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/8.jpg)
• Antiferromagnetic superexchange dominatesin magnetic insulators and semiconductors ���� no spontaneous magnetization
NiO, MnSe, EuTe, …
• Exceptions-- ferrimagnets (two ions or two spin states co-exist)
NiO(Fe2O3), Mn4N, …
-- double exchange (two charge states co-exist)
LaMnO3 � La1-xSrxMnO3 (holes in d band)
-- ferromagnetic superexchange dominates
EuO, ZnCr2Se4, … TC ≈ 100 K IBM, MIT, Tohoku, … ‘60-’70
Search for ferromagnetic semiconductors
Mn+3 Mn+4
Mn Se Mn
![Page 9: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/9.jpg)
Spintronics -- materials aspectSpintronics -- materials aspect
Why to do not combine complementary resources of ferromagnets and semiconductors?
TopGaN
� ferromagnetic semiconductors – multifunctional materials
• making good semiconductors of magnetic oxidescf. J. Fontcuberta, R. Gross, N. Keller, ....
![Page 10: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/10.jpg)
Spintronics -- materials aspectSpintronics -- materials aspect
Why to do not combine complementary resources of ferromagnets and semiconductors?
TopGaN
� ferromagnetic semiconductors – multifunctional materials
• making good semiconductors of magnetic oxides
• making good semiconductors magneticR.R. Gałąłąłąłązka et al. (Warsaw)’77- ; H. Ohno et al. (IBM, Tohok u) ’89 –see, Spin Physics, Nature Milestones (2008)
![Page 11: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/11.jpg)
• Intrinsic DMS – random antiferromagnets
Cd1-xMnxTe
Zn1-xCoxO
Making DMS ferromagnetic
B
![Page 12: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/12.jpg)
• Intrinsic DMS – random antiferromagnets
Cd1-xMnxTe
Zn1-xCoxO
Making DMS ferromagnetic
B
• p+-type DMS – Zener/RKKY ferromagnets
IV-VI: p-Pb 1-x-y-MnxSnyTe
Story et al. (Warsaw, MIT) PRL’86
III-V: In 1-x-MnxAs Ohno et al. (IBM) PRL’92
Ga1-x-MnxAs Ohno et al. (Tohoku) APL’96
II-VI: Cd 1-xMnxTe/Cd1-x-yZnxMgyTe:N QW Haury et al.(Grenoble,Warsaw) PRL’97
Zn1-xMnxTe:N Ferrand et al. (Grenoble, Linz, Warsaw) Physica B’99, PRB’01
TC ≈≈≈≈ 100 K for x = 0.05
![Page 13: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/13.jpg)
p-d Zener/RKKY model of hole-controlled ferromagnetism in DMS
Driving force: lowering of the hole energy due to redistribution bet ween hole spin subbands split by p-d exchange interaction
T.D. , Y. Merle d’Aubigné PRB’97-T. D, H. Ohno – Science’00 -Jungwirth et al. (Austin/Prague) ’99-
kkkk
EF
![Page 14: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/14.jpg)
p-d Zener/RKKY model of hole-controlled ferromagnetism in DMS
Driving force: lowering of the hole energy due to redistribution bet ween hole spin subbands split by p-d exchange interaction, ∆∆∆∆ ~ ββββM
No adjustable parametersTC ~ xββββ2ρρρρ(s)
DOS
Essential ingredient: Complexity of the valence band structurehas to be taken into account
M
kkkk
EF
T.D. , Y. Merle d’Aubigne PRB’97-T. D, H. Ohno – Science’00 -T. Jungwirth et al. (Austin/Prague) ’99-
![Page 15: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/15.jpg)
Mn-based p-type DMSwith valence-band hole mediated ferromagnetism
10 100
CdTe
InSb
ZnTe
InAsGaSb
GaAs
Curie temperature (K)
300
Expl.:Tohoku, Tokyo, Grenoble, Wuerzburg, PSU, Notre Dame ,Lund, UCSB,Nottingham, Prague…
xMn = 5%p = 3.5x1020 cm -3
• TC ≈≈≈≈ ΘΘΘΘCW
• TC (p,x) consistent withp-d Zener model
![Page 16: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/16.jpg)
Mn-based p-type DMSwith valence-band hole mediated ferromagnetism
10 100
CdTe
InSb
ZnTe
InAsGaSb
GaAs
Curie temperature (K)
300
xMn = 5%p = 3.5x1020 cm -3
• TC ≈≈≈≈ ΘΘΘΘCW
• TC (p,x) consistent withp-d Zener model
• not double exchange• not impurity band models
Expl.:Tohoku, Tokyo, Grenoble, Wuerzburg, PSU, Notre Dame ,Lund, UCSB,Nottingham, Prague…
see, T. Jungwirth, … T.D., PRB’07
![Page 17: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/17.jpg)
Spintronic functionalities of ferro DMS
• spin injection (Tohoku/St. Barbara Nature’99, JJAP’01, PRB’02
APL’03,’06; IMEC/Warsaw APL’04, PRB’05)
• GMR, TMR, TAMR (Tohoku Physica’00,’04; Thaless PRL’03, Wuerzburg PRL’04,’05, Nottingham PRL’05)
• RTD (Tohoku APL’98, Tokyo APL’06; Thaless PRL’07)
• ,,,,,,,,
Magnetisation manipulation by:• light (Tokyo PRL’97, Grenoble/Warsaw PRL’97,’02)
• electric field (Tohoku/Warsaw Nature’00,’08 Grenoble/Warsaw PRL’02)
• electric current in trilayer structures(Tohoku PRL’04, Orsay PRB’06)
• domain-wall displacement induced by electric current (Tohoku, Nature ’04, Science’07, Tohoku/Warsaw PRL’06 )
![Page 18: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/18.jpg)
Tuning of magnetic ordering by electric field (ferro-FET) (In,Mn)As
MMMM
I
VVVVHHHH
![Page 19: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/19.jpg)
Tuning magnetic ordering by electric field (ferro-FET) (In,Mn)As
MMMM
I
VVVVHHHH
H. Ohno … TD., Nature 2000
![Page 20: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/20.jpg)
lhhh
eEpitaxial-strain-induced magnetic anisotropy
Sawicki et al. (Warsaw, Wuerzburg) PRB’04after T.D. et al. (Warsaw, Tohoku) PRB ‘01
Ga1-xMnxAs/GaAs ���� compressive strain
jz = ±±±±3/22 4 6 8 10 12 14 16 18 20
0
5
10
15
20
As grown
28282828 h ann.
57575757 h ann.
Perp
end
icula
r com
ponent
of R
EM
[ a
.u. ]
Temperature [ K ]
x = 0.053
2 4 6 8 10 12 14 16 18 20 22
0
5
10
15
20
In-p
lane c
om
ponent
of R
EM
[ a
.u. ]
Tem perature [ K ]
![Page 21: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/21.jpg)
lhhh
eEpitaxial-strain-induced magnetic anisotropy
0.0 0.2 0.4 0.6 0.8 1.0
1
0.1
Hole
density [ 10
20 c
m-3 ]
T / TC
after T.D. et al. (Warsaw, Tohoku) PRB ‘01
Ga1-xMnxAs/GaAs ���� compressive strain
jz = ±±±±3/2
jz = ±±±±1/2
theoryx = 0.053
2 4 6 8 10 12 14 16 18 20
0
5
10
15
20
As grown
28282828 h ann.
57575757 h ann.
Perp
end
icula
r com
ponent
of R
EM
[ a
.u. ]
Temperature [ K ]
x = 0.053
2 4 6 8 10 12 14 16 18 20 22
0
5
10
15
20
In-p
lane c
om
ponent
of R
EM
[ a
.u. ]
Tem perature [ K ]
Sawicki et al. (Warsaw, Wuerzburg) PRB’04
![Page 22: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/22.jpg)
lhhh
eReorientation transition –theory and expt.
2 4 6 8 10 12 14 16 18 20
0
5
10
15
20
As grown
28282828 h ann.
57575757 h ann.
Perp
end
icula
r com
ponent
of R
EM
[ a
.u. ]
Temperature [ K ]
anne
alin
gan
neal
ing
0.0 0.2 0.4 0.6 0.8 1.0
1
0.1
Hole
density [ 10
20 c
m-3 ]
T / TC
after T.D. et al. (Warsaw, Tohoku) PRB ‘01
Ga1-xMnxAs/GaAs ���� compressive strain
jz = ±±±±3/2
jz = ±±±±1/2
theoryx = 0.053
x = 0.053
2 4 6 8 10 12 14 16 18 20 22
0
5
10
15
20
In-p
lane c
om
ponent
of R
EM
[ a
.u. ]
Tem perature [ K ]
Sawicki et al. (Warsaw, Wuerzburg) PRB’04(Warsaw, Nottingham) RB’05, PRL’05
![Page 23: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/23.jpg)
Combining FET and anisotropy
![Page 24: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/24.jpg)
Strategies for high TC in hole-controlled DMS
• Strategies:
-- increasing p and/or x in existing ferromagnetic DMS (Ga,Mn)As
T.D. et al. (Warsaw, Tohoku, Grenoble) Science’00
![Page 25: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/25.jpg)
Strategies for high TC in hole-controlled DMS
• Strategies:
-- increasing p and/or x in existing ferromagnetic DMS (Ga,Mn)As
-- searching for DMS with greater coupling constant xββββ2ρρρρ(EF)nitrides, oxides
T.D. et al. (Warsaw, Tohoku, Grenoble) Science’00
![Page 26: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/26.jpg)
Strategies for high TC in hole-controlled DMS
• Strategies:
-- increasing p and/or x in existing ferromagnetic DMS (Ga,Mn)As
-- searching for DMS with greater coupling constant xββββ2ρρρρ(EF)nitrides, oxides
• Obstacles:
-- self-compensation
-- tight binding of holes by TM ions (Zhang-Rice singlet)
-- solubility limits
T.D. et al. (Warsaw, Tohoku, Grenoble) Science’00
![Page 27: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/27.jpg)
Where are we? (Ga,Mn)As
Wang/ Sawicki (Nottingham, Warsaw) ICPS’04
remanent magnetization and 1/ χχχχ vs. T
140 150 160 170 180 190 200
RE
MS
pont
aneo
us
Temperature [ K ]
χχ χχ-1 [ a.u. ]
8% (Ga,Mn)As
1/χχχχ
MREM TC = 173 K
Sendai, Tokyo, Notre Dame, PSU, Lund, Wuerzburg, IME C, UCSB,…
remanent magnetization
Olejnik et al. (Prague) cond-mat/08
annealed
8% (Ga,Mn)Asannealed/etched/annealed
TC = 180 K
![Page 28: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/28.jpg)
Self-compensation
![Page 29: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/29.jpg)
TC in (Ga,Mn)As
The progress due to increase of p by low temperature annealing�
out diffusion of Mn I:Máca and Mašek (Prague) PRB’02, Yu et al. (Berkeley,Notre Dame) PRB’02; APL’04Edmonds et al. (Nottingham, Warsaw) PRL’04
Nottingham, Sendai, Tokyo, Notre Dame, PSU, Lund, Wu erzburg, IMEC, St. Barbara, Prague…
Rec
ord
Cur
ie te
mpe
ratu
re (
K)
1990 1995 2000 2005 20100
50
100
150
200
250
300
350
400
Date
180 Klow Tannealing
low Tannealing
saturation(?)
saturation(?)
![Page 30: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/30.jpg)
Beyond (Ga,Mn)AsStrong coupling
![Page 31: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/31.jpg)
0 10 20 30 40 50
-2
-1
0
1
2
3
4
GaN
CoMnFe
ZnO
InAsGaAs
β = − 0.057 eV nm3
CdTeZnTeCdSe
CdS ZnSeZnS
Exc
hang
e en
ergy
, −βN
o
Cation density, No (nm-3)
solid symbols: magnetoopticsopen symbols: photoemission
lattice parameter
Chemical trends in exchange energy βN0
photo-emission
XASFujimori et al.
(Tokyo)
![Page 32: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/32.jpg)
0 10 20 30 40 50
-2
-1
0
1
2
3
4
GaN
CoMn
:Mn
:Fe
ZnO
Mn
Co
GaN
MnFe
ZnO
Co
InAsGaAs
β = − 0.057 eV nm3
CdTeZnTeCdSe
CdS ZnSeZnS
Exc
ha
ng
e e
ne
rgy,
−βN
o
Cation density, No (nm -3)
solid symbols: magnetoopticsopen symbols: photoemission
Exchange energy βN0Photoemission vs. magnetooptics
magneto
-opticsPacuski et al.
(Warsaw/Grenoble/Linz)PRB’06’07, PRL’08
photo-emission
XASFujimori et al.
(Tokyo)
![Page 33: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/33.jpg)
Mn
U
Spin splitting
weak coupling
VCA, MFAsplitting ~ M
![Page 34: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/34.jpg)
Mn
Ubonding
Mn
U
Spin splitting
weak coupling strong coupling
reversed signreduce magnitude
T.D. PRB’08
VCA, MFAsplitting ~ M
![Page 35: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/35.jpg)
Effect of strong coupling on ferromagnetism
deep hole trap formed
����
no holes
����
no efficient ferro-magnetism according to p-d Zener model
Mn acceptor energy
![Page 36: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/36.jpg)
Effect of strong p-d coupling on TC in p-type DMS
Cur
ie te
mpe
ratu
re
TM, hole concentration
strong couplingnitrides, oxides
strong couplingnitrides, oxides
arsenides, selenidesweak coupling
arsenides, selenidesweak coupling
MFAVCA
MFAVCA
MITMIT
![Page 37: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/37.jpg)
Properties of implanted Ga1-xMnxP
Scarpulla et al. (Berkeley) PRL’05localisation
x = 6%, TC ≅ 55 K
TC TC
![Page 38: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/38.jpg)
Magnetic properties of uniform Ga1-xMnxN
weak FM
x = 6%, TC ≅ 8 K
Sarigiannidou et al. (Grenoble) PRB’06
![Page 39: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/39.jpg)
DMS, DMO, and non-magnetic materials showingspontaneous magnetization at 300 K
wz-c-(Ga,Mn)N, (Ga,Fe)N, (In,Mn)N, (Al,Mn)N, (Ga,Cr)N, (Al,Cr)N
(Zn,Mn)O, (Zn,Ni)O, (Zn,Co)O, (Zn,V)O, (Zn,Fe,Cu)O, (Zn,Cu)O
(Zn,Cr)Te
(Ti,Co)O2, (Ti,V)O2, (Ti,Cr)O2, (Sn,Co)O2, (Sn,Fe)O2, (Hf,Co)O2
(Ga,Mn)As, (In, Mn)As, (Ga,Mn)Sb, (Ga,Mn)P:C
(Cd,Ge,Mn)P2, (Zn,Ge,Mn)P2, (Cd,Ge,Mn)As 2, (Zn,Sn,Mn)As 2
(Ge,Mn), (Ge,Cr), (Ge,Mn,Fe), (Si,Fe), (Si,Mn), (SiC,Fe)
no valence band holes
![Page 40: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/40.jpg)
DMS, DMO, and non-magnetic materials showingspontaneous magnetization at 300 K
wz-c-(Ga,Mn)N, (Ga,Fe)N, (In,Mn)N, (Al,Mn)N, (Ga,Cr)N, (Al,Cr)N
(Zn,Mn)O, (Zn,Ni)O, (Zn,Co)O, (Zn,V)O, (Zn,Fe,Cu)O, (Zn,Cu)O
(Zn,Cr)Te
(Ti,Co)O2, (Ti,V)O2, (Ti,Cr)O2, (Sn,Co)O2, (Sn,Fe)O2, (Hf,Co)O2
(Ga,Mn)As, (In, Mn)As, (Ga,Mn)Sb, (Ga,Mn)P:C
(Cd,Ge,Mn)P2, (Zn,Ge,Mn)P2, (Cd,Ge,Mn)As 2, (Zn,Sn,Mn)As 2
(Ge,Mn), (Ge,Cr), (Ge,Mn,Fe), (Si,Fe), (Si,Mn), (SiC,Fe)
(La,Ca)B 6, CaB2C2, C, C60, HfO2, ZnO, (Ga,Gd)N, (Ga,Eu)N ...
no valence band holes , no TM ions
![Page 41: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/41.jpg)
DMS, DMO, and non-magnetic materials showingspontaneous magnetization at 300 K
wz-c-(Ga,Mn)N, (Ga,Fe)N, (In,Mn)N, (Al,Mn)N, (Ga,Cr)N, (Al,Cr)N
(Zn,Mn)O, (Zn,Ni)O, (Zn,Co)O, (Zn,V)O, (Zn,Fe,Cu)O, (Zn,Cu)O
(Zn,Cr)Te
(Ti,Co)O2, (Ti,V)O2, (Ti,Cr)O2, (Sn,Co)O2, (Sn,Fe)O2, (Hf,Co)O2
(Ga,Mn)As, (In, Mn)As, (Ga,Mn)Sb, (Ga,Mn)P:C
(Cd,Ge,Mn)P2, (Zn,Ge,Mn)P2, (Cd,Ge,Mn)As 2, (Zn,Sn,Mn)As 2
(Ge,Mn), (Ge,Cr), (Ge,Mn,Fe), (Si,Fe), (Si,Mn), (SiC,Fe)
(La,Ca)B 6, CaB2C2, C, C60, HfO2, ZnO, (Ga,Gd)N, (Ga,Eu)N ...
no valence band holes , no TM ionsoften supported by DFT computations
![Page 42: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/42.jpg)
DMS, DMO, and non-magnetic materials showingspontaneous magnetization at 300 K
wz-c-(Ga,Mn)N, (Ga,Fe)N, (In,Mn)N, (Al,Mn)N, (Ga,Cr)N, (Al,Cr)N
(Zn,Mn)O, (Zn,Ni)O, (Zn,Co)O, (Zn,V)O, (Zn,Fe,Cu)O, (Zn,Cu)O
(Zn,Cr)Te
(Ti,Co)O2, (Ti,V)O2, (Ti,Cr)O2, (Sn,Co)O2, (Sn,Fe)O2, (Hf,Co)O2
(Ga,Mn)As, (In, Mn)As, (Ga,Mn)Sb, (Ga,Mn)P:C
(Cd,Ge,Mn)P2, (Zn,Ge,Mn)P2, (Cd,Ge,Mn)As 2, (Zn,Sn,Mn)As 2
(Ge,Mn), (Ge,Cr), (Ge,Mn,Fe), (Si,Fe), (Si,Mn), (SiC,Fe)
(La,Ca)B 6, CaB2C2, C, C60, HfO2, ZnO, (Ga,Gd)N, (Ga,Eu)N ...
no valence band holes , no TM ionsoften supported by DFT computations
… no devices …
![Page 43: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/43.jpg)
DMS, DMO, and non-magnetic materials showingspontaneous magnetization at 300 K
wz-c-(Ga,Mn)N, (Ga,Fe)N, (In,Mn)N, (Al,Mn)N, (Ga,Cr)N, (Al,Cr)N
(Zn,Mn)O, (Zn,Ni)O, (Zn,Co)O, (Zn,V)O, (Zn,Fe,Cu)O, (Zn,Cu)O
(Zn,Cr)Te
(Ti,Co)O2, (Ti,V)O2, (Ti,Cr)O2, (Sn,Co)O2, (Sn,Fe)O2, (Hf,Co)O2
(Ga,Mn)As, (In, Mn)As, (Ga,Mn)Sb, (Ga,Mn)P:C
(Cd,Ge,Mn)P2, (Zn,Ge,Mn)P2, (Cd,Ge,Mn)As 2, (Zn,Sn,Mn)As 2
(Ge,Mn), (Ge,Cr), (Ge,Mn,Fe), (Si,Fe), (Si,Mn), (SiC,Fe)
(La,Ca)B 6, CaB2C2, C, C60, HfO2, ZnO, (Ga,Gd)N, (Ga,Eu)N ...
origin of UFO ?
![Page 44: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/44.jpg)
SQUID studies of DMS and DMO in Warsaw
M. Sawicki et al. (Warsaw):
wz-c-(Ga,Mn)N, (Ga,Fe)N(Ga,Mn)As
(Zn,Mn)Te:N, P(Cd,Mn)Te, (Cd,Mn)Se
(Cd,Cr)Te, (Zn,Cr)Se
(Zn,Mn)O, (Zn,Co)O, (Zn,Cr)O
![Page 45: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/45.jpg)
Experimental challenges
-- precipitates of magnetic metals (Co, Fe)
-- contamination by magnetic nanoparticles(growth, processing)
-- sample but also substrate, interface, holder,…
-- SQUID: residual fields, software, ….
![Page 46: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/46.jpg)
Beyond solubility limit
![Page 47: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/47.jpg)
Spinodal decomposition in MBE-grown (Ga,In)N
(Ga,Cr)N
controlled by:-- solubility limit?-- surface phase separation and kinetic barrier?-- ??
XRD
Doppalapudi et al. (Boston) JAP’98Liliental-Weber et al. (Berkeley), JEM’05
![Page 48: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/48.jpg)
Model for high TC DMS
T. D. ICPS’04, MRS’04, Nature Mat. Sept.’06 -K. Sato, H. Katayama-Yoshida, P. Dederichs, JAAP‘05 -S. Kuroda et al. (Tsukuba/Warsaw) Nature Mat.’07
Model for DMS and DMO beyond solubility limit • phase separation or spinodal decomposition into regions with
low and high concentration of magnetic constituents
• FM or AFM regions with high concentration determine magnetic properties (through high blocking temperature)
![Page 49: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/49.jpg)
Model for high TC DMS
T. D. ICPS’04, MRS’04, Nature Mat. Sept.’06 -K. Sato, H. Katayama-Yoshida, P. Dederichs, JAAP‘05 -S. Kuroda et al. (Tsukuba/Warsaw) Nature Mat.’07
Model for DMS and DMO beyond solubility limit • phase separation or spinodal decomposition into regions with
low and high concentration of magnetic constituents
• FM or AFM regions with high concentration determine magnetic properties (through high blocking temperature)
spinodal decomposition hard to detect:
-- crystallographic structure remains uniform
-- magnetic regions may gather at surface or interface
-- element specific 3D nanoanalyzer required
![Page 50: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/50.jpg)
Phase separations in (Ga,Mn)AsPhase separations in (Ga,Mn)As
� depending on growth conditions precipitates or spino dal decomposition
Moreno et al. (Berlin) JAP’02
� control magnetic properties De Boeck et al. (IMEC) APL’96
� enhance magnetooptical effects (MCD) Akinaga et al. (Tsukuba) APL’00; Shimizu et al. (Tokyo) APL’01; Yokoyama et al. (Toky o) JAP’05
� affect conductance and Hall effect Heimbrodt et al. (Marburg) PRB’04
spinodaldecomposition
hexMnAs
GaAs
TC ≈≈≈≈ 320 K
H (Oe)
zbMnAs
GaAs
TC ≈≈≈≈ 350 K
DMS with spinodal decomposition� functional high TC composite systems
Mn-rich regions:
![Page 51: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/51.jpg)
Spinodal decomposition in DMS from TEM + EDS
Dots(Ga,Mn)N
(Ga,Cr)N
Martínez-Criado,et al. (Grenoble) APL’05 Shuto et al. (Tokyo) APL’07
(Ge,Fe)(Ga,Fe)N
Bonanni (Linz/Warsaw) PRB’07
![Page 52: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/52.jpg)
Nanocolumns(Ge,Mn)
(Ga,Cr)N
Jamet et al. (Grenoble) Nature Mat. ‘06
Guo et al. (Arizona) JMMM’06
(Al,Cr)N
![Page 53: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/53.jpg)
Nanocolumns(Ge,Mn)
(Ga,Cr)N
Jamet et al. (Grenoble) Nature Mat. ‘06
Guo et al. (Arizona) JMMM’06
(Al,Cr)N
Nanomagnets in formof dots or nanocolumns
![Page 54: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/54.jpg)
Fukushima et al. (Osaka) phys.stat.sol. (c)’06
Spinodal decomposition: modelingFormation of tunnel/Coulomb blockade junctions
![Page 55: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/55.jpg)
How to control spinodal decomposition?
![Page 56: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/56.jpg)
Self-organized quantum dots in semiconductors
(Ga,Cr)N
spinodal decomposition controlled by epitaxial strain
Springholz et al. (Linz) Science’98
InAs in GaAs PbSe in (Pb,Eu)Te
![Page 57: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/57.jpg)
Effect of doping on spinodal decomposition
TM charge state is controlled by co-doping with shall ow
impurities. Because of Coulomb repulsion spinodal
decomposition is blocked if TM is charged
Mn+3EF
GaNEF
Mn+2
GaN:Si
Cr+2EF
ZnTe
EF
Cr+3
ZnTe:N
T.D., Nature Mat.’06L.-H. Ye et al. (NWU) PRB’06
![Page 58: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/58.jpg)
K. Osuch & T. Dietl (2006)
-150
-100
-50
0
50
100
Cr0 Cr1+ Cr2+ Cr3+
Bin
ding
Ene
rgy
[meV
]
Cr4+
Formation energy of Cr-Cr pair in ZnTe
S. Kuroda … T.D.(Tsukuba, Warsaw)
Nature Mat., ’07
Effect of charge state on binding energy of Cr pair
lower limit because p-d hybridization
overestimated by LSDA
![Page 59: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/59.jpg)
Effect of co-doping on magnetism
S. Kuroda … T.D. (Tsukuba, Warsaw) Nature Mat., ’07
-1.0 -0.5 0.0 0.5 1.0-2
-1
0
1
2I-doped
N-dopedundoped
T = 2KH ⊥⊥⊥⊥ plane
Mag
neti
zati
on [[ [[
µµ µµB /
Cr
]] ]]
Magnetic Field [T]
x = 0.05
[N] ~ 3 x1020 cm-3 Cr3+
Te-rich growth Cr2+/Cr3+
[I] ~ 2 x 1018 cm-3 Cr2+
![Page 60: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/60.jpg)
0
100
200
300
ΘΘΘΘP
Cri
tica
l Tem
p. [
K]
240220200 180 160 140 120TCdI2
[[[[ oC]]]]
1019 1018 1017
TB
TC
[ I ] [[[[ cm-3]]]]
50nm
Optimized
I-doped
Inhomogeneous
Effect of co-doping on Cr distribution
S. Kuroda ... T.D. (Tsukuba, Warsaw) Nature Mat., ’0 7
![Page 61: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/61.jpg)
1020 10210
100
200
300
TCΘΘΘΘ
P
Cri
tica
l Tem
p. [
K]
[N] [[[[ cm-3]]]]0
100
200
300
ΘΘΘΘP
Cri
tica
l Tem
p. [
K]
240220200 180 160 140 120TCdI2
[[[[ oC]]]]
1019 1018 1017
TB
TC
[ I ] [[[[ cm-3]]]]
N-doped
50nm
Optimized
I-dopedN-doped
Inhomogeneous Homogeneous
Effect of co-doping on Cr distribution
S. Kuroda … T.D. (Tsukuba, Warsaw) Nature Mat., ’07
![Page 62: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/62.jpg)
Ferromagnetism of (Ga,Mn)N – effect of co-doping
(Ga,Mn)Nx = 0.2%
TC >> 300 K
(Ga,Mn)N, x = 0.2%TC ���� 0 for Si doping
(Ga,Mn)N:Si
Reed et al. (NCSU) APL’05
cf. Kane et al. (Georgia) JCG’06
Effect of co-doping and stoichiometry on TC also in (Zn,Mn)O and (Zn,Co)O
cf. Kittilstved et al. (Washington) PRL’05
![Page 63: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/63.jpg)
(Ga,Fe)N -- ferromagnetic response vs. growth rate
A. Bonanni …. T.D. (Linz/Warsaw/Grenoble/Prague) P RL’08
0 5 100.0
0.2
0.4
0.6
(Ga,Fe)N
nF
erro
/(n
Fer
ro +
nF
e3+)
TMGa [ sccm ]
Cp2Fe = 300 sccmT = 5K
Fe3N
![Page 64: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/64.jpg)
Effect of Si-dopingFerromagnetism of (Ga,Fe)N – effect of co-doping
ferromagnetic responsevs. growth rate
synchrotron XDR
A. Bonanni …. T.D. (Linz/Warsaw/Grenoble/Prague) P RL’08
![Page 65: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/65.jpg)
Effect of Si-dopingFerromagnetism of (Ga,Fe)N – effect of co-doping
A. Bonanni …. T.D. (Linz/Warsaw/Grenoble/Prague) P RL’08
disolution of spinodal decomposition
![Page 66: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/66.jpg)
Effect of Si-dopingSummary: distribution of TM in DMS
Fe3N
A. Bonanni …. T.D. (Linz/Warsaw/Grenoble/Prague) P RL’08
![Page 67: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/67.jpg)
SUMMARY cont.
1. New coherent magnetic compounds formed
2. High TC, TN; high blocking temperature
� spontaneous magnetization at high temperatures
3. Nanoassembling (shape, size) can be controlled in situby growth conditions/co-doping
![Page 68: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/68.jpg)
SUMMARY cont.
1. New coherent magnetic compounds formed
2. High TC, TN; high blocking temperature
� spontaneous magnetization at high temperatures
3. Nanoassembling (shape, size) can be controlled in situby growth conditions/co-doping
4th generation epitaxy
![Page 69: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/69.jpg)
SUMMARY cont.
1. New coherent magnetic compounds formed
2. High TC, TN; high blocking temperature
� spontaneous magnetization at high temperatures
3. Nanoassembling (shape, size) can be controlled in situby growth conditions/co-doping
4. Functionalities:
� nanometalization � nanoelectronics, optoelectronics, plasmonics
� large magnetotransport effects � field sensors
� large magnetooptical effects � optical isolators, tunable photonic crystals
� spintronic structure �high density MRAMs/race track memories/logic
� large spin entropy � thermoelectricity
� ….
![Page 70: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/70.jpg)
OUTLOOK
race track memory logic gates
Parkin et al. (IBM) SPINTECH’05, Science’06
Dery et al. (UCSD) Nature’07
magnetooptical devices metallization
Self-organised nanomagnets in semiconductors -- media for:
I
![Page 71: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/71.jpg)
Phase diagram of La1-xCaxMnO3
DMS and DMO: interactions determine spatial distribu tion of both carriers and localised spins
![Page 72: Krakow 08 a dietl - AGH University of Science and Technology · Magnetyzm w półprzewodnikach Tomasz DIETL Institute of Physics, Polish Academy of Sciences, Laboratory for Cryogenic](https://reader031.fdocuments.in/reader031/viewer/2022031500/5c7713f209d3f291718bd2b5/html5/thumbnails/72.jpg)