Composition Dependence of the Magnetization-Induced Uniaxial Anisotropy in both Normal and Unconstrained Ni–Fe Thin Films

Abstract

The magnetization‐induced uniaxial anisotropy has been measured for normal and unconstrained vacuum‐deposited Permalloy films containing 0% to 40% Fe. It is observed that the unconstrained films possess anisotropies that are quite similar to the limiting values obtainable in magnetic annealing of bulk specimens. The difference between the constrained and unconstrained films is in reasonable agreement with West's version of the magnetostrictive constraint theory, although some disparity exists in films containing Fe in excess of the zero magnetostriction composition. These experiments offer support of the model that the anisotropy in thin films is a combination of the constraint and the directional ordering mechanisms.