Temperature dependence of magnetic resonance in ferrimagnetic GdFeCo alloys

TL;DR

This paper develops a comprehensive macroscopic theory and presents experimental data on the temperature-dependent magnetic resonance behavior of ferrimagnetic GdFeCo alloys, bridging the gap between antiferromagnetic and ferromagnetic dynamics.

Contribution

The work introduces a unified theoretical model for ferrimagnetic resonances across temperature ranges and experimentally demonstrates temperature-insensitive Gilbert damping in GdFeCo alloys.

Findings

The theory describes ferrimagnetic resonances across the angular momentum compensation point.

Experimental results show Gilbert damping is insensitive to temperature.

The framework aids future studies of ferrimagnetic dynamics.

Abstract

We provide a macroscopic theory and experimental results for magnetic resonances of antiferromagnetically-coupled ferrimagnets. Our theory, which interpolates the dynamics of antiferromagnets and ferromagnets smoothly, can describe ferrimagnetic resonances across the angular momentum compensation point. We also present experimental results for spin-torque induced ferrimagnetic resonance at several temperatures. The spectral analysis based on our theory reveals that the Gilbert damping parameter, which has been considered to be strongly temperature dependent, is insensitive to temperature. We envision that our work will facilitate further investigation of ferrimagnetic dynamics by providing a theoretical framework suitable for a broad range of temperatures.