Influence of valence states and vacancy defects on the magnetic properties of Mn doped InN

Abstract

The effects of valence states and vacancy defects on the properties of Mn doped InN were systematically investigated by the first-principle generalized gradient approximation + U (GGA + U) calculations. Calculations show the systems exhibits lower formation energy and better stability after Mn doping. The energies calculation results show that the double Mn2+ doped InN exhibits only antiferromagnetism, but mixed Mn2+/3+ doping in the nearest neighboring cation sites and mixed Mn2+/3+ doping with vacancy defects can obtain a better ferromagnetism and high Curie temperature. The electronic structures indicate that the p-d exchange interaction and double exchange interaction play important roles in the magnetic formation of the doping system. The vacancies in mixed Mn2+/3+ doped InN enhance the dominance of the p-d exchange interaction, and favor the doping system to obtain a high Curie temperature. It can be inferred that the mixed 2+/3 + valence of Mn ions and introduction of vacancy defects in InN is beneficial to stabilize the ferromagnetism.