Structural, magnetic and Magnetic-Microstructural properties of sputtered FeCoNi thin films

Abstract

This paper reports the effect of growth rate and substrate temperature on the composition, structure, microstructure, magnetic and magnetic microstructural properties of Fe-Co-Ni alloy thin films. 200 nm thick Fe-Co-Ni thin films were grown by high power impulse magnetron sputtering on Si 〈100〉 at different growth rates (viz., 1 – 2.4 Å/s). Films were also thermally processed by modifying the substrate temperatures. Room temperature deposited films showed the presence of FCC structure for all the films. However, films grown at higher substrate temperatures displayed presence of BCC phase co-existing with FCC phase. High saturation magnetization combined with low coercivity has been obtained for the Fe-Co-Ni films grown at higher growth rate and enhanced substrate temperature. Magnetization and magnetic microstructural studies using Kerr microscopy showed anisotropic magnetic properties along the plane of the film with the magnetization reversal dominated by domain wall motion and domain wall rotation.