Roles of oxygen vacancies on ferromagnetism in Ni doped In2O3: A hybrid functional study

摘要

The roles of oxygen vacancies on the electronic and magnetic properties of Nidoped In$_2$O$_3$ have been studied by first-principles calculations based onhybrid functional theory. Our results predict that the Ni-doped In$_2$O$_3$system displays a ferromagnetic semiconducting character. However, the presenceof oxygen vacancies results in antiferromagnetic coupling between theneighboring Ni pair bridged by an oxygen vacancy. The antiferromagneticcoupling is found to arise from the predominant role of superexchange due tothe strong Ni 3d-O 2p hybridization. Consequently, the oxygen vacancies play akey role in the lower saturation magnetization of Ni:In$_2$O$_3$polycrystalline sample, as observed in experiments.