The enhancement of ferromagnetism in uniaxially stressed diluted magnetic semiconductors

TL;DR

This paper predicts that applying uniaxial stress to p-type diluted magnetic semiconductors can significantly enhance their ferromagnetic transition temperature by shifting from Heisenberg to Ising model behavior, broadening ferromagnetic stability.

Contribution

It introduces a new mechanism for ferromagnetic enhancement in stressed DMS by comparing Heisenberg and Ising models within a random field approximation.

Findings

Ising model predicts a larger ferromagnetic phase region than Heisenberg model.

Uniaxial stress effectively transforms the magnetic interactions, increasing $T_c$.

Stress-induced anisotropy expands the conditions for ferromagnetism in DMS.

Abstract

We predict a new mechanism of enhancement of ferromagnetic phase transition temperature $T_c$ in uniaxially stressed diluted magnetic semiconductors (DMS) of p-type. Our prediction is based on comparative studies of both Heisenberg (inherent to undistorted DMS with cubic lattice) and Ising (which can be applied to strongly enough stressed DMS) models in a random field approximation permitting to take into account the spatial inhomogeneity of spin-spin interaction. Our calculations of phase diagrams show that area of parameters for existence of DMS-ferromagnetism in Ising model is much larger than that in Heisenberg model.