Electronic and magnetic properties of GaMnAs: Annealing effects

TL;DR

This study investigates how annealing at 250°C affects the electrical and magnetic properties of GaMnAs and heterostructures, revealing conductivity increases, saturation of hole density and Curie temperature, and enhancement of Curie temperature by InGaMnAs layers.

Contribution

It provides new insights into the effects of annealing duration and InGaMnAs incorporation on GaMnAs magnetic and electronic properties.

Findings

Conductivity increases monotonously with annealing time.

Hole density and Curie temperature saturate after 30 minutes of annealing.

InGaMnAs layers significantly enhance the Curie temperature.

Abstract

The effect of short-time and long-time annealing at 250C on the conductivity, hole density, and Curie temperature of GaMnAs single layers and GaMnAs/InGaMnAs heterostructures is studied by in-situ conductivity measurements as well as Raman and SQUID measurements before and after annealing. Whereas the conductivity monotonously increases with increasing annealing time, the hole density and the Curie temperature show a saturation after annealing for 30 minutes. The incorporation of thin InGaMnAs layers drastically enhances the Curie temperature of the GaMnAs layers.