Shanghai Key Laboratory of Modern Metallurgy & Material Processing German-Sino Workshop on EPM, October, 16-19, 2005, Dresden, Germany 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

Electrochemical Crystallization in HSMF Influence on mass transport Charge Transfer Influence on mass transport MHD effect  E0 Influence on Surface Diffusion、Necleation、Crystal Growth? Me2+ H2O Surface Diffusion Nucleation Influence on electron transfer kinetics ? Crystal Growth Metal Membrane Boundary Layer Bulk Solution

Variation of Free Energy in the process of Electro-deposition of NiFe membrane Magnetic susceptibility (χ) of Ni and Fe atoms are higher than that of other non magnetism atoms The χ data is very lacking, and the magnetism of ions in solution are not very clear

Sketch Map of Experimental Equipment Nitrogen Thermocouple Water-cooling Pipe Supercon-ductive Coil Heater Electrolyte Heat Insulator Quartz Pipe Electrode B + - Fix Block PID Temperature Controller B I B//I B Magnetic Field Center I Nickel Plate B⊥I Copper Foil

Distribution of High Static Magnetic Field

Effect of magnetic field on electrodeposited Ni-Fe membrane When I⊥B Magnetic Field Center

Surface SEM pictures of NiFe membrane electrodeposited in various magnetic fields(J=4A/dm2)

Across-section SEM pictures of NiFe membrane electrodeposited in various magnetic fields(J=4A/dm2) ( -electrodeposit growth direction )

XRD patterns of the NiFe membranes (111) (111) (200) (200) (220) (220) 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 XRD patterns of the NiFe membranes electrodeposited in different magnetic flux density

Crystal Orientation Discussion 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；

Effect of MFD on Crystal Orientation Coefficient

(Fe wt%= 0T-12.71%; 6T-14.99%; 10T-23.32%; 12T-26.10%.) EDS analysis of the samples electrodeposited in different magnetic fields (Fe wt%= 0T-12.71%; 6T-14.99%; 10T-23.32%; 12T-26.10%.)

The relation between saturation magnetization of the samples and preparation magnetic flux density

Effect of magnetic field on electrodeposited Ni-Fe membrane When 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 B J SEM pictures of the across-section of NiFe membrane electrodeposited in parallel magnetic fields (J=4A/dm2)

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)

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%.)

The relation between saturation magnetization of the samples and preparation magnetic field

0T 10T

(J= a-1A/dm2; b-2A/dm2; c-3A/dm2; d-4A/dm2; e-6A/dm2) 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)

FSEM pictures of the across-section of NiFe membrane 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 d e f 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)

SEM pictures of the across-section of NiFe membrane 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)

In Homogeneous Magnetic Field Sketch Map of Nucleation and Crystal Growth when B⊥I In Homogeneous Magnetic Field Trajectory of Ions Sphere Crystal nucleus Metal atom Hydration Ions Metal Crystal Outer Helmholtz area FL I B FE Trajectory of Ions Boundary Layer Bulk solution (a) 0T (b) B1(B1≠0T) B2(B2≥10T)

Sketch Map of Nucleation and and Crystal Growth when B//I In Homogeneous Magnetic Field Direction of magnetic field (B) Magnetic field Anode Direction of electric field (I) Bubble Initial velocity (v0) Cathode Migration of atoms in Horizontal direction

Electro-depostion of NiFe Membrane in Gradient Magnetic Field -400T2/m

Magnetic Field Gradient Element Wt % At% +400T2/m FeK 38.37 39.56 NiK 61.63 60.44 0T2/m 22.84 23.73 77.16 76.27 29.39 30.44 70.61 69.56

Sketch Map of Nucleation and and Crystal Growth when B//I and in Gradient Magnetic Field J B I B//I B

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 .

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