Non-monotonic variation of anomalous Hall effect with spin orbit coupling strength

TL;DR

This study investigates how the anomalous Hall effect in FePt films varies non-monotonically with spin orbit coupling strength, revealing complex dependencies on chemical ordering and resistivity components.

Contribution

It demonstrates the non-monotonic relationship between anomalous Hall resistivity components and spin orbit coupling in FePt films, linked to chemical ordering.

Findings

Anomalous Hall resistivity is proportional to spontaneous magnetization.

Resistivity components fit a combined linear and quadratic model.

Spin orbit coupling strength increases monotonically with chemical ordering S.

Abstract

For L1(0) FePt films, the anomalous Hall resistivity is found to be proportional to spontaneous magnetization $M_{\mathrm{S}}$. After the $M_{\mathrm{S}}$ temperature effect is eliminated, $\rho_{\mathrm{xyo}}$ can be fitted by $\rho_{\mathrm{xyo}}=a_{\mathrm{o}}\rho_{\mathrm{xx}}+ b_{\mathrm{o}}\rho_{\mathrm{xx}}^{\mathrm{2}}$. $a_{\mathrm{o}}$ and $b_{\mathrm{o}}$ change non-monotonically with chemical long range ordering degree $S$. Accordingly, it is indicated that for L1(0) FePt films the spin orbit coupling strength increases monotonically with increasing $S$.