We theoretically investigate disorder effects on the ferromagnetic transition ('Curie') temperature Tc in dilute III1−xMnxV magnetic semiconductors (e.g. Ga1−xMnxAs) where a small fraction (x≈0.01−0.1) of the cation atoms (e.g. Ga) are randomly replaced by the magnetic dopants (e.g. Mn), leading to long-range ferromagnetic ordering for T<Tc. We find that Tc is a complicated function of at least eight different parameters including carrier density, magnetic dopant density, and carrier mean free path; nominally macroscopically similar samples could have substantially different Curie temperatures. We provide simple physically appealing prescriptions for enhancing Tc in diluted magnetic semiconductors, and discuss the magnetic phase diagram in the system parameter space.
@article{arxiv.cond-mat/0403059,
title = {Enhancing $T_c$ in ferromagnetic semiconductors},
author = {S. Das Sarma and E. H. Hwang and D. J. Priour},
journal= {arXiv preprint arXiv:cond-mat/0403059},
year = {2009}
}