Electrodeposition of soft CoFe alloys

Abstract

CoFe alloy films plated from a chloride-based electrolyte exhibit a saturation induction of about 20,000 Gauss. Easy-axis coercive field exhibits a minimum (approximately 3 Oe) at the composition of 11.5% Fe (by weight). The composition of zero magnetostriction is estimated at about 10.5% Fe. X-ray diffraction and TEM are used to investigate possible mechanisms for the steep increase of the coercive field on either side of the optimal composition. Microstructural changes due to thermal annealing, as determined by X-ray diffraction, have a predictable effect on the film magnetic properies. Domain configurations observed by means of Kerr microscopy in head-shaped elements suggest that CoFe could be an attractive high-moment alternative to Permalloy.