Relation of Curie temperature and conductivity: (Ga,Mn)As alloy as a case study

TL;DR

This paper investigates the relationship between Curie temperature and conductivity in (Ga,Mn)As alloys, using first-principles calculations to account for defects and comparing results with experimental data.

Contribution

It presents a self-consistent first-principles approach to simultaneously calculate Curie temperature and conductivity, explicitly considering compensating defects in (Ga,Mn)As alloys.

Findings

Good agreement with experiments when Mn-interstitials dominate

The presence of compensating defects significantly affects magnetic and electronic properties

Theoretical calculations successfully reproduce the non-trivial dependence of T_C and conductivity

Abstract

Experimental investigations of diluted magnetic semiconductors indicate a strong relation between Curie temperature and conductivity. Both quantities depend non trivially on the concentration of magnetic impurities, the carrier density, and the presence of compensating defects. We calculate both Curie temperature and conductivity of (Ga,Mn)As alloys in a selfconsistent manner based on the same first principles Hamiltonian in which the presence of compensating defects is taken into account. The effect of As-antisites and Mn-interstitials is determined separately and a good agreement between theory and experiment exists only in the case where the dominating mechanism of is due to the Mn-interstitials.