Transport and magnetic properties of LT annealed Ga1-xMnxAs

TL;DR

This study investigates how low temperature annealing affects the magnetic and transport properties of Ga1-xMnxAs epilayers, achieving Curie temperatures above 110K and up to 127K, with optimal conditions identified.

Contribution

It provides a comprehensive analysis of annealing effects on GaMnAs, establishing optimal annealing procedures for enhanced magnetic properties.

Findings

Curie temperatures above 110K achieved

Annealing causes significant changes in magnetic and transport properties

Optimal annealing occurs near the growth temperature

Abstract

We present the results of low temperature (LT) annealing studies of Ga1-xMnxAs epilayers grown by low temperature molecular beam epitaxy in a wide range of Mn concentrations (0.01<x<0.084). Transport measurements in low and high magnetic fields as well as SQUID measurements were performed on a wide range of samples, serving to establish optimal conditions of annealing. Optimal annealing procedure succeeded in the Curie temperatures higher than 110K. The highest value of Curie temperature estimated from the maximum in the temperature dependence of zero-field resistivity (Tr) was 127K. It is generally observed that annealing leads to large changes in the magnetic and transport properties of GaMnAs in the very narrow range of annealing temperature close to the growth temperature.