Nanosecond magnetic relaxation processes in ultrathin metallic films prepared by MBE

Abstract

Magnetic relaxation processes were investigated by ferromagnetic resonance (FMR) using crystalline Cr/Fe/GaAs(001) ultrathin film structures grown by molecular beam epitaxy (MBE). For Fe films thicker than 1.5 nm the extrinsic relaxation term showed evidence of two magnon scattering. Above 10 GHz the in-plane FMR linewidth was linearly dependent on the microwave frequency with an appreciable zero-frequency offset. The zero frequency offset measures the strength of extrinsic damping. The in-plane Gilbert damping includes both the intrinsic and extrinsic Gilbert contributions in qualitative agreement with recent predictions by Arias and Mills. © 2001 The American Physical Society.