We have investigated the interplay between disorder and ferromagnetism in III1-xMnx V semiconductors. Our study is based on a model in which S = 5/2 Mn local moments are exchange coupled to valence-band holes that interact via Coulomb interactions with each other, with ionized Mn acceptors, and with the antisite defects present in these materials. We find quasiparticle participation ratios consistent with a metal-insulator transition that occurs in the ferromagnetic state near x∼0.01. By evaluating the distribution of exchange mean fields at Mn moment sites, we provide evidence in favor of the applicability of impurity-band magnetic-polaron and hole-fluid models on insulating and metallic sides of the phase transition, respectively.
|Number of pages||6|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2003 Apr 1|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics