Valence state-dependent ferromagnetism in Mn-doped NiO thin films

Abstract

Manipulating the ferromagnetism of diluted magnetic semiconductors by tuning the valence state of doped ions is found to be achievable in Mn-doped NiO. First-principles calculations predict that the interactions between substitutional Mn 3+ ions in NiO are ferromagnetic, while the Mn 2+-Mn 2+ interactions are antiferromagnetic. This scenario is experimentally supported by a great enhancement of saturation magnetization with increased Mn 3+/Mn 2+ ratio in Mn-doped and (Mn, Li)-codoped NiO. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.