Effect of interfacial spin mixing conductance on gyromagnetic ratio of Gd substituted Y$_{3}$Fe$_{5}$O$_{12}$

TL;DR

This paper investigates how interfacial spin mixing conductance influences the gyromagnetic ratio in Gd-substituted Y$_3$Fe$_5$O$_{12}$, revealing effects beyond previous theoretical assumptions about its imaginary part.

Contribution

It demonstrates that damping differences caused by spin mixing conductance can alter the gyromagnetic ratio in ferrimagnetic materials, challenging prior theoretical views.

Findings

Damping variations affect gyromagnetic ratio in Gd-YIG.

Spin mixing conductance influences ferrimagnetic damping.

The effect extends beyond the negligible imaginary part assumption.

Abstract

Due to its low intrinsic damping, Y$_3$Fe$_5$O$_{12}$ and its substituted variations are often used for ferromagnetic layer at spin pumping experiment. Spin pumping is an interfacial spin current generation in the interface of ferromagnet and non-magnetic metal, governed by spin mixing conductance parameter $G^{\uparrow\downarrow}$. $G^{\uparrow\downarrow}$ has been shown to enhance the damping of the ferromagnetic layer. The theory suggested that the effect of $G^{\uparrow\downarrow}$ on gyromagnetic ratio only come from its negligible imaginary part. In this article, we show that the different damping of ferrimagnetic lattices induced by $G^{\uparrow\downarrow}$ can affect the gyromagnetic ratio of Gd-substituted Y$_3$Fe$_5$O$_{12}$.