Ferromagnetic Resonance Controlled by Micro-regions in Fe-Co Based Thin Film

Abstract

FeCoBSi amorphous thin films containing circular antidots are fabricated on the silicon substrate by photolithography, DC magnetron sputtering and lift-off patterning. The films are divided into several micro-regions by antidots which have different demagnetizing field. The magnetic properties of these thin films are studied by measurement of the dynamic magnetic spectrum and hysteresis loop. The demagnetizing field in micro-regions deteriorates macroscopic uniaxial magnetic anisotropy (UMA). Diverse resonance peaks are found for various antidots. The dipolar coupling among micro-regions and the natural resonance independent part of micro-regions determine the dynamic magnetic spectrum together. The mechanisms of ferromagnetic resonance are proposed to be related to the special domain structure caused by the demagnetizing field in corresponding micro-regions. In order to study the configuration of magnetic moments in micro-regions, the object oriented micromagnetic framework (OOMMF) is used to simulate the dynamic magnetization process.