Evaluation of edge domains in giant magnetoresistive junctions

William Frost,Takeshi Seki,Atsufumi Hirohata,Eiji Saitoh,Takahide Kubota,Koki Takanashi,Rafael Ramos

doi:10.1063/5.0049315

Abstract

We demonstrate that the spin-Seebeck effect can be used to estimate the volume of edge domains formed in a giant magnetoresistive (GMR) device. The thermal gradient induced by Joule heating can be harnessed by the addition of a ferromagnetically insulating channel of Fe2O3 on the sides of the GMR pillar. This generates a spin wave in Fe2O3, which couples with the free-layer edge magnetization and controls the reversal of the ferromagnetic layers in one direction only, increasing the current density from ( 1.1 ± 0.1 ) ×107 A/cm2 to ( 7.0 ± 0.5 ) × 10 7 A/cm2. By simple assumption, we estimate the effect of the edge domain on magnetization reversal to be 10%–15% by spin-transfer torque.

Highlights

If this spin current can be introduced to the ferromagnetic layers of a magnetoresistive device, the switching behavior can be manipulated
We demonstrate that the spin-Seebeck effect can be used to estimate the volume of edge domains formed in a giant magnetoresistive (GMR) device
This spin-wave generation controls the current density for switching and introduces a strong asymmetry due to the coercivity differences between the Heusler alloy layers and the Ferromagnetic insulators (FMIs), allowing us to estimate the volume of the edge domains in a pillar

Summary

Introduction

If this spin current can be introduced to the ferromagnetic layers of a magnetoresistive device, the switching behavior can be manipulated. We demonstrate that the spin-Seebeck effect can be used to estimate the volume of edge domains formed in a giant magnetoresistive (GMR) device.

Results

Conclusion