Post on 15-Jan-2016
description
Effect of HSMF on Electrodeposited Ni-Fe Membrane-- Crystal Morphology and
Magnetism Performance
Yunbo Zhong, Yanling Wen, Zhongming Ren, Kang Deng, Kuangdi Xu
Shanghai Key Laboratory of Modern Metallurgy & Material Processing
German-Sino Workshop on EPM, October, 16-19, 2005, Dresden, Germany
Influence on electron transfer kinetics ?
Influence on mass transportMHD effect
Influence on Surface Diffusion 、 Necleation 、Crystal Growth?
Electrochemical Crystallization in HSMF
H2OMe2+
MetalMembrane
E0
ChargeTransfer
SurfaceDiffusionNucleation
CrystalGrowth
Bulk Solution
BoundaryLayer
2
02BUM
2
02BU Ls
M
Variation of Free Energy in the process of Electro-deposition of NiFe membrane
The χ data is very lacking, and the magnetism of ions in solution are not very clear
Magnetic susceptibility (χ) of Ni and Fe atoms are higher than that of other non magnetism atoms
PID TemperatureController
B
I
B I⊥
B
I
B//I
Magnetic Field Center
Nitrogen
Thermocouple
Water-cooling Pipe
Supercon-ductive Coil
HeaterElectrolyte
Heat Insulator
Quartz Pipe
Electrode
B
+ -
Fix Block
Sketch Map of Experimental Equipment
Nickel Plate
Copper Foil
0
1
2
3
4
5
6
7
8
9
10
11
-20 -15 -10 -5 0 5 10 15 20
Distance to Magnetic Field Center, z /cm
Mag
netic
Flu
x D
ensi
ty, B
/T
- 500
- 400
- 300
- 200
- 100
0
100
200
300
400
500
- 20 - 15 - 10 - 5 0 5 10 15 20
Di stance to Magneti c Fi el d Center, Z/ cm
BdB/
dz,T2/m
Distribution of High Static Magnetic Field
Effect of magnetic field on electrodeposited Ni-Fe membrane
When I⊥B
B
IMagnetic Field
Center
Surface SEM pictures of NiFe membrane electrodeposited in various magnetic fields(J=4A/dm2)
0T 4T 6T
8T 10T 12T
Across-section SEM pictures of NiFe membrane electrodeposited in various magnetic fields(J=4A/dm2)
( -electrodeposit growth direction )
0T 4T 6T
8T 12T10T
B
XRD patterns of the NiFe membranes
electrodeposited in different magnetic flux density
Strength ratio of three main peaks: I(111):I(200):I(220)=
( 0T)100:54.3:4.3; (04T)100:24.7:6.2; (06T)100:26.9:6.4; (08T)100:28.8:7.1; (10T)100:28.2:8.4; (12T)100:19.1:6.6
(111)
(200)
(220)
(111)
(200)(220)
M - Crystal orientation coefficient ;I(hkl) - Measured value of the (hkl) plane diffraction peaks ;I0(hkl) - Standard value of the (hkl) plane diffraction
peaks in PDF card ;
Crystal Orientation Discussion
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
0 2 4 6 8 10 12 14
Magnetic Flux Density/T
Ori
enta
tion
Coe
ffic
ient
(111)
(200)
(220)
Effect of MFD on Crystal Orientation Coefficient
EDS analysis of the samples electrodeposited in different magnetic fields
(Fe wt%= 0T-12.71%; 6T-14.99%; 10T-23.32%; 12T-26.10%.)
0T 6T
10T 12T
The relation between saturation magnetization
of the samples and preparation magnetic flux density
40
50
60
70
80
90
100
110
120
0 2 4 6 8 10 12 14
B/T
Ms/
emu/
g
Effect of magnetic field on electrodeposited Ni-Fe membrane
When B//I
B
I
B//I
Magnetic Field Center
SEM pictures of the surface of NiFe membrane
electrodeposited in parallel magnetic fields(J=4A/dm2)
0T 4T 6T
8T 10T 12T
6T0T
SEM pictures of the across-section of NiFe membrane electrodeposited in parallel magnetic fields (J=4A/dm2)
10T 12T
4T
8T
BJ
XRD patterns of the NiFe membranes
electrodeposited in different static magnetic fields
(Strength ratio of three main peaks : I(111):I(200):I(220)= (0T)100:41.1:4.5; (6T)100:25.8:6.6; (10T)100:27.2:7.6; (12T)100:26.1:7.4)
0.00.2
0.40.60.8
1.01.2
1.41.6
0 2 4 6 8 10 12 14
Magnetic Flux Density/T
Orie
ntat
ion
Coe
ffici
ent (111)
(200)
(220)
Analysis of crystal orientation coefficient of the samples
EDS analysis of the samples
electrodeposited in different magnetic fields
(Fe wt%= 0T-14.13%; 6T-14.12%; 10T-15.17%; 12T-14.47%.)
0T 6T
10T 12T
The relation between saturation magnetization
of the samples and preparation magnetic field
0T
10T
SEM pictures of the surface of NiFe membrane electrodeposited without magnetic field
(J= a-1A/dm2; b-2A/dm2; c-3A/dm2; d-4A/dm2; e-6A/dm2)
a b c
d e
a b c
d e
FSEM pictures of the across-section of NiFe membrane
electrodeposited without magnetic field
(J= a-1A/dm2; b-2A/dm2; c-4A/dm2; d-5A/dm2; e-6A/dm2)
Fig.17-a SEM pictures of the surface of NiFe membrane
electrodeposited in 10T static magnetic field
(J= a-1A/dm2; b-2A/dm2; c-3A/dm2; d-4A/dm2; e-5A/dm2; f-6A/dm2)
a b c
d e f
a b
c d
SEM pictures of the across-section of NiFe membrane
electrodeposited in 10T static magnetic field
(J= a-2A/dm2; b-3A/dm2; c-4A/dm2; d-6A/dm2)
(a) 0T (b) B1(B1≠0T) B2(B2≥10T)
Hydration Ions Metal atom
Metal Crystal
Sphere Crystal nucleus
FL
IBFE
Outer Helmholtz area
Bulk solution
Trajectory of Ions
Boundary LayerTrajectory of Ions
Sketch Map of Nucleation and Crystal Growth when B⊥I
In Homogeneous Magnetic Field
Initial velocity (v0)
BubbleDirection of electric field (I)
Direction of magnetic field (B)
Cathode
Anode
Sketch Map of Nucleation and and Crystal Growth when B//I
In Homogeneous Magnetic Field
Magnetic field
Migration of atoms in Horizontal direction
Electro-depostion of NiFe Membrane in Gradient Magnetic Field
+400T2/m 0 -400T2/m
Magnetic Field Gradient
Element Wt % At%
+400T2/mFeK 38.37 39.56
NiK 61.63 60.44
0T2/mFeK 22.84 23.73
NiK 77.16 76.27
+400T2/mFeK 29.39 30.44
NiK 70.61 69.56
B
I
B//I
B
J
Sketch Map of Nucleation and and Crystal Growth when B//I and in Gradient Magnetic Field
Conclusions
In HSMF, Strengthened MHD effect may influence the crystal morphology of electrodeposited NiFe membrane remarkably, so do the mass transfer process;
Both perpendicular and parallel magnetic field can make the crystal (111) plane texture reinforced;
The iron contents and the saturation magnetization were increased in perpendicular magnetic field but unchanged in parallel one .
Thank you
for your attentions!