Relation of thickness and some physical properties of NiFe thin films

Abstract

The magnetic properties of rf sputtered Ni8Fe,9films were studied as a function of thickness from < 100 to —1200 A. In contrast to some recently reported studies, there was no evidence of an oscillatory dependence of resistivity on Ap as a function of thickness. The magnetoresistance, resistance, coercivity, and anisotropy field varied smoothly with thickness. In contrast, the magnetostriction Ashad a minimum of — 1.5x10“6at —300 A. The saturation magnetic moment did not decrease with thickness over the thickness range studied here. The derived magnetoresistance of an “infinitely” thick film was 3.92% compared to the bulk value of —4%. The analysis indicates that surface and grain-boundary scattering are the primary cause of lower than bulk values of magnetoresistance in these thin permalloy films. © 1991, American Vacuum Society. All rights reserved.