On the magnetoelastic contribution to the magnetic anisotropy of thin epitaxial Permalloy films: an ab initio study

Abstract Permalloy films are often used in the magnetic thin film technology. It is expected that in this material the magnetoelastic coupling of the magnetization to the epitaxial film strain does not produce undesired magnetic anisotropy, because the linear magnetoelastic bulk coefficient B 1 of Permalloy is near-zero. It is shown by means of the ab initio density functional electron theory that the nonvanishing nonlinear magnetoelastic couplings also do not lead to a considerable anisotropy. Explicit values for two of the nonlinear magnetoelastic coupling coefficients are given.