Abstract
First-principle calculations of the electronic structure and magnetic interaction of GaN:Gd have been performed within the generalized gradient approximation (GGA) of the density functional theory with the on-site Coulomb energy taken into account (also referred to as ). The ferromagnetic coupling is found to be over 2 orders of magnitude larger than the exchange coupling. The experimental colossal magnetic moments and room-temperature ferromagnetism in GaN:Gd reported recently are explained by the interaction of Gd spins via coupling involving holes introduced by intrinsic defects such as Ga vacancies.
- Received 24 September 2007
DOI:https://doi.org/10.1103/PhysRevLett.100.127203
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