Ferromagnetic ordering is reported in the post-annealed samples of Co doped n-GaN formed by Co+ implantation. A maximum Curie temperature ~ 250K is recorded for the sample with 8 atomic percent Co. Particle induced x-ray emission-channeling study confirmed the substitutional Co in Ga lattice site. Local atomic arrangement around magnetic impurities is also analyzed using Raman study. A disordered model with carrier mediated coupling of localized magnetic moments is made responsible for the observed ferromagnetic ordering.
@article{arxiv.0708.2217,
title = {Ferromagnetism in cobalt doped n-GaN},
author = {S. Dhara and B. Sundaravel and K. G. M. Nair and R. Kesavamoorthy and M. C. Valsakumar and T. V. Chandrasekhar Rao and L. C. Chen and K. H. Chen},
journal= {arXiv preprint arXiv:0708.2217},
year = {2007}
}