Perpendicular magnetic anisotropy in Co$_2$MnGa

TL;DR

This paper demonstrates perpendicular magnetic anisotropy in Co$_2$MnGa thin films within a trilayer structure, revealing a thickness- and temperature-dependent spin reorientation transition studied via anomalous Hall effect.

Contribution

It reports the observation of perpendicular magnetic anisotropy in Co$_2$MnGa and analyzes the spin reorientation transition and anomalous Hall effect mechanisms.

Findings

Perpendicular magnetic anisotropy observed up to 3.5 nm thickness.

Spin reorientation transition depends on temperature and thickness.

Anomalous Hall effect scales with longitudinal resistivity, indicating intrinsic and side-jump mechanisms.

Abstract

We report perpendicular magnetic anisotropy in the ferromagnetic Heusler alloy Co$_2$MnGa in a MgO/Co$_2$MnGa/Pd trilayer stack for Co$_2$MnGa thicknesses up to 3.5 nm. There is a thickness- and temperature-dependent spin reorientation transition from perpendicular to in-plane magnetic anisotropy which we study through the anomalous Hall effect. From the temperature dependence of the anomalous Hall effect, we observe the expected scaling of $\rho_{xy}^{AHE}$ with $\rho_{xx}$, suggesting the intrinsic and side-jump mechanisms are largely responsible for the anomalous Hall effect in this material.