Enhanced spin-orbit torques in MnAl/Ta films with improving chemical ordering

TL;DR

This study demonstrates that improving chemical ordering in MnAl/Ta films via annealing enhances spin-orbit torques, effective fields, and interfacial spin transparency, leading to better control of magnetic switching.

Contribution

It reveals that annealing-induced chemical ordering significantly boosts spin-orbit torques and interfacial spin transparency in MnAl/Ta films, a novel approach for magnetic device optimization.

Findings

Enhanced spin-orbit torques after annealing.

Increased dampinglike and fieldlike effective fields.

Inverse relationship between HD and MS, linear dependence of HF on 1/MS.

Abstract

We report the enhancement of spin-orbit torques in MnAl/Ta films with improving chemical ordering through annealing. The switching current density is increased due to enhanced saturation magnetization MS and effective anisotropy field HK after annealing. Both damplinglike effective field HD and fieldlike effective field HF have been increased in the temperature range of 50 to 300 K. HD varies inversely with MS in both of the films, while the HF becomes liner dependent on 1/MS in the annealed film. We infer that the improved chemical ordering has enhanced the interfacial spin transparency and the transmitting of the spin current in MnAl layer.