Anomalous Hall Effect in Ge(1-x-y)Pb(x)Mn(y)Te Composite System

TL;DR

This study investigates the magnetotransport properties of a Ge-Pb-Mn-Te compound, revealing a spin-glass-like magnetic state, variable-range hopping conduction, and a temperature-independent anomalous Hall effect primarily driven by extrinsic skew scattering.

Contribution

It provides the first detailed analysis of the anomalous Hall effect and magnetotransport mechanisms in Ge(1-x-y)Pb(x)Mn(y)Te composite systems.

Findings

Spin-glass-like magnetic behavior with TSG = 97.5 K.

Observation of the anomalous Hall effect with hysteresis.

Extrinsic skew scattering identified as the main AHE mechanism.

Abstract

The purpose of this study was to investigate the magnetotransport properties of the Ge(0.743)Pb(0.183)Mn(0.074)Te mixed crystal. The results of magnetization measurements indicated that the compound is a spin-glass-like diluted magnetic semiconductor with critical temperature TSG = 97.5 K. Nanoclusters in the sample are observed. Both, matrix and clusters are magnetically active. Resistivity as a function of temperature has a minimum at 30 K. Below the minimum a variable-range hopping is observed, while above the minimum a metallic-like behavior occurs. The crystal has high hole concentration, p = 6.6E20 cm-3, temperature-independent. Magnetoresistance amplitude changes from -0.78 to 1.18% with increase of temperature. In the magnetotransport measurements we observed the anomalous Hall effect (AHE) with hysteresis loops. Calculated AHE coefficient, RS = 2.0E6 m3/C, is temperature independent. The analysis indicates the extrinsic skew scattering mechanism to be the main physical mechanism responsible for AHE in Ge(0.743)Pb(0.183)Mn(0.074)Te alloy.