Using {\it ab initio} band structure calculations and symmetry arguments, we show that the magnetic property of Ga1−xGdxN is drastically different from TM-doped GaN. The coupling between Gd atoms in the alloy is antiferromagnetic, but the ferromagnetic phase can be stabilized by introducing electrons. Furthermore, we propose a model that may explain the recently observed colossal magnetic moments in this system, based on the polarization of donor electrons.
@article{arxiv.cond-mat/0507257,
title = {Electron-induced stabilization of ferromagnetism in GaGdN},
author = {Gustavo M. Dalpian and Su-Huai Wei},
journal= {arXiv preprint arXiv:cond-mat/0507257},
year = {2009}
}