Collinear and non-collinear spin structures of wurtzite phase CoO often appearing in nano-sized samples are investigated using first-principles density functional theory calculations. We examined the total energy of several different spin configurations, electronic structure and the effective magnetic coupling strengths. It is shown that the AF3-type antiferromagnetic ordering is energetically most stable among possible collinear configurations. Further, we found that a novel spiral spin order can be stabilized by including the relativistic spin-orbit coupling and the non-collinearity of spin direction. Our result suggests that a non-collinear spin ground state can be observed in the transition-metal-oxide nanostructures which adds an interesting new aspect to the nano-magnetism study.
@article{arxiv.1305.6496,
title = {Collinear and non-collinear spin ground state of wurtzite CoO},
author = {Myung Joon Han and Heung-Sik Kim and Dong Geun Kim and Jaejun Yu},
journal= {arXiv preprint arXiv:1305.6496},
year = {2013}
}