Anisotropic Gilbert damping in perovskite La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ thin film

TL;DR

This study provides experimental evidence of anisotropic Gilbert damping in epitaxial La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ films, revealing its dependence on magnetization orientation and strain, which is crucial for spintronics.

Contribution

First experimental demonstration of anisotropic Gilbert damping in La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ films using broadband ferromagnetic resonance.

Findings

Anisotropic damping with twofold symmetry observed at room temperature.

Magnetization orientation affects the band structure and damping.

Strain manipulation can tailor damping anisotropy.

Abstract

The viscous Gilbert damping parameter governing magnetization dynamics is of primary importance for various spintronics applications. Although, the damping constant is believed to be anisotropic by theories. It is commonly treated as a scalar due to lack of experimental evidence. Here, we present an elaborate angle dependent broadband ferromagnetic resonance study of high quality epitaxial La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ films. Extrinsic effects are suppressed and we show convincing evidence of anisotropic damping with twofold symmetry at room temperature. The observed anisotropic relaxation is attributed to the magnetization orientation dependence of the band structure. In addition, we demonstrated that such anisotropy can be tailored by manipulating the stain. This work provides new insights to understand the mechanism of magnetization relaxation.