Crystal structure and magnetic softness of Fe-Si polycrystalline films

Abstract

Magnetic softness of polycrystalline Fe-based alloy films is investigated. From calculation of magnetocrystalline anisotropy and magnetostriction assuming the magnetization is confined in a certain crystal plane of bcc Fe or Fe-Si alloy, Fe alloy films with (111) orientation parallel to the film plane are expected to have good magnetic softness. Fe-6.9 wt. % Si polycrystalline films with various crystallographic orientations such as (100), (110), or (111) oriented parallel to the film plane plane are deposited on underlayers such as MgO, ZnO, and ZnSe by a high-rate sputtering system. Fe-Si films on ZnSe underlayers with (111) orientation exhibit smaller Hc and better thermal stability than those of films with other orientations. Magnetic softness and thermal stability are improved for the double-layered films with those orientations. For multilayered Fe-6.9 wt. % Si films on ZnSe underlayers, the Hc of deposited films is about 0.5 Oe, and is stable against annealing up to 500 °C.