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Enhancing $T_c$ in ferromagnetic semiconductors

S. Das Sarma·E. H. Hwang·D. J. Priour Jr
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Abstract

We theoretically investigate disorder effects on the ferromagnetic transition ('Curie') temperature $T_c$ in dilute III$_{1-x}$Mn$_x$V magnetic semiconductors (e.g. Ga$_{1-x}$Mn$_x$As) where a small fraction ($x \approx 0.01-0.1$) of the cation atoms (e.g. Ga) are randomly replaced by the magnetic dopants (e.g. Mn), leading to long-range ferromagnetic ordering for $T<T_c$. We find that $T_c$ 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 $T_c$ in diluted magnetic semiconductors, and discuss the magnetic phase diagram in the system parameter space.

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S. Das Sarma, E. H. Hwang, D. J. Priour Jr. 2004-03-01. Enhancing $T_c$ in ferromagnetic semiconductors. https://doi.org/10.1103/physrevb.70.161203

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