Magnetic Properties of Electroless-Deposited NiFeB and Electrodeposited NiFe Alloy Thin Films

Madoka TAKAI  Kensuke KAGEYAMA  Sanae TAKEFUSA  Akiyoshi NAKAMURA  Tetsuya OSAKA 

Publication
IEICE TRANSACTIONS on Electronics  Vol.E78-C  No.11  pp.1530-1535
Publication Date: 1995/11/20
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Ultra High Density Information Storage Technologies)
Category: 
Keyword: 
electroless-deposition,  NiFe thin film,  soft magnetic properties,  magnetostriction,  structure, 

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Summary: 
The magnetic properties and the structure of electroless-deposited NiFeB films were investigated in comparison with those of electrodeposited NiFe films. The electroless-deposited NiFeB film with 27at% Fe content had the lowest coercivity, H, as low as 0.5 Oe with a saturation magnetic flux density, Bs, of 1.0 T. The saturation magnetostriction, λ, and the uniaxial magnetic anisotropy, Hk, were 5.010-6 and 10 Oe, respectively, which were larger than those of the conventional, electrodeposited permalloy film. The permeability of as-deposited Ni70Fe27B3 film was 1000 at 1 MHz. In order to improve the permeability, the film was heated at 200 in a magnetic field applied in the hard-axis direction to decrease the Hk value, and the permeability became 2000 at 1 MHz. The crystal structure and grain size of NiFeB and NiFe films were investigated by XRD, THEED and TEM. Both films with low Hc had an fcc structure; the grain size of the NiFeB film was smaller than 10 nm, while that of the NiFe film was larger, approximately 20 nm. The results suggested that the electroless-deposited NiFeB film had a larger magnetic anisotropy than the electrodeposited NiFe film. Moreover, the films with Hc less than 10 Oe ded not show clear difference between their TEM bright images and THEED patterns.