Coupling interaction and surface energy in FeBSi/Si and FeBSi/Pt multilayered structures

Abstract

An effective coupling field between ferromagnetic sublayers was found as a function of the thickness t of the non-magnetic medium in multilayered structures of FeBSi/Si and FeBSi/Pt. The surface energy anisotropy constant was also determined for FeBSi/Pt films. We used ferromagnetic resonance and spin wave resonance at room temperature for the study of the properties of multilayered structures of metallic glasses of FeBSi separated by silicon or platinum. Thin films were obtained by the r.f. sputtering technique. Some basic magnetic parameter such as saturation magnetization and exchange constant were found from the ferromagnetic and spin wave resonances of single films of metallic glasses. The additional anisotropy field of the effective coupling is of the easy-plane type when silicon is the non-magnetic medium for t greater than 1.5 nm. For platinum, the effective field exhibits an easy-axis anisotropy along the film normal and the surface anisotropy constant varies from sample to sample in the range from 0.2 to 0.6 erg cm −2. We also observed a weak t dependence of the surface anisotropy field.