%0 Journal Article
%T Most spin-1/2 transition-metal ions do have single ion anisotropy
%A Jia Liu
%A Hyun-Joo Koo
%A Hongjun Xiang
%A Reinhard K. Kremer
%A Myung-Hwan Whangbo
%J Physics
%D 2014
%I arXiv
%R 10.1063/1.4896148
%X The cause for the preferred spin orientation in magnetic systems containing spin-1/2 transition-metal ions was explored by studying the origin of the easy-plane anisotropy of the spin-1/2 Cu2+ ions in CuCl2.2H2O, LiCuVO4, CuCl2 and CuBr2 on the basis of density functional theory and magnetic dipole-dipole energy calculations as well as a perturbation theory treatment of the spin-orbit coupling. We find that the spin orientation observed for these spin-1/2 ions is not caused by their anisotropic spin exchange interactions, nor by their magnetic dipole-dipole interactions, but by the spin-orbit coupling associated with their crystal-field split d-states. Our study also predicts in-plane anisotropy for the Cu2+ ions of Bi2CuO4 and Li2CuO2. The results of our investigations dispel the mistaken belief that magnetic systems with spin-1/2 ions have no magnetic anisotropy induced by spin-orbit coupling.
%U http://arxiv.org/abs/1409.2795v2