Hydrostatic pressure influence on TC in (Ga,Mn)As

The influence of hydrostatic pressure on the Curie temperature TC of thin ferromagnetic (Ga,Mn)As layers is studied. New experimental data unambiguously point to both positive and negative pressure-induced changes of Curie temperature. The positive pressure coefficient is observed for samples with relatively high values of TC and can be quantitatively described by the p−d Zener model of carrier-mediated ferromagnetism within the six-band k⋅p formalism and the ab initio approach. First-principles calculations of structural, electronic, and magnetic properties of (Ga,Mn)As show that antiferromagnetic coupling of substitutional Mn atoms with interstitial ones may account for a decrease of TC under pressure in samples having a substantial concentration of interstitial Mn.