Negative magnetoresistance and anomalous Hall effect in GeMnTe-SnMnTe spin-glass-like system

TL;DR

This study investigates the magnetotransport properties of GeMnTe-SnMnTe spin-glass-like crystals, revealing negative magnetoresistance from weak localization and spin disorder, and an extrinsic anomalous Hall effect influenced by Mn content.

Contribution

It provides new insights into the mechanisms behind magnetoresistance and AHE in GeMnTe-SnMnTe systems, highlighting the role of extrinsic scattering processes.

Findings

Negative magnetoresistance attributed to weak localization and spin disorder scattering.

Pronounced hysteretic anomalous Hall effect with small temperature dependence.

AHE mainly due to extrinsic mechanisms like skew scattering and side jump processes.

Abstract

Magnetotransport properties of spin-glass-like Ge/1-x-y/Sn/x/Mn/y/Te mixed crystals with chemical composition changing in the range of 0.083 < x < 0.142 and 0.012 < y < 0.119 are presented. The observed negative magnetoresistance we attribute to two mechanisms i.e. weak localization occurring at low fields and spin disorder scattering giving contribution mainly at higher magnetic fields. A pronounced hysteretic anomalous Hall effect (AHE) was observed. The estimated AHE coefficient shows a small temperature dependence and is dependent on Mn-content, with changes in the range of 10E-7 < R_S < 10E-6 m^3/C. The scaling law analysis has proven that the AHE in this system is due to the extrinsic mechanisms, mainly due to the skew scattering accompanied with the side jump processes.