Thermal spin current generation in the multifunctional ferrimagnet Ga$_{0.6}$Fe$_{1.4}$O$_{3}$

TL;DR

This study demonstrates efficient thermal spin current generation in a Ga$_{0.6}$Fe$_{1.4}$O$_{3}$ (GFO) ferrimagnetic insulator using thermo-spin measurements, highlighting its potential for energy-efficient spintronic devices with electric-field control.

Contribution

It provides the first quantitative analysis of spin Seebeck effect in GFO/Pt bilayers, showing comparable spin current generation to YIG/Pt and enabling electric-field manipulation of magnetic properties.

Findings

GFO/Pt bilayer exhibits a measurable spin Seebeck effect.

Spin current generation in GFO/Pt is comparable to YIG/Pt.

Electric-field control of magnetic properties is feasible in GFO.

Abstract

In recent years, multifunctional materials have attracted increasing interest for magnetic memories and energy harvesting applications. Magnetic insulating materials are of special interest for this purpose, since they allow the design of more efficient devices due to the lower Joule heat losses. In this context, Ga$_{0.6}$Fe$_{1.4}$O$_3$ (GFO) is a good candidate for spintronics applications, since it can exhibit multiferroicity and presents a spin Hall magnetoresistance similar to the one observed in a yttrium iron garnet (YIG)/Pt bilayer. Here, we explore GFO utilizing thermo-spin measurements in an on-chip approach. By carefully considering the geometry of our thermo-spin devices we are able to quantify the spin Seebeck effect and the spin current generation in a GFO/Pt bilayer, obtaining a value comparable to that of YIG/Pt. This further confirms the promises of an efficient spin current generation with the possibility of an electric-field manipulation of the magnetic properties of the system in an insulating ferrimagnetic material.