Ferromagnetic coupling and the effect of Fe-dt2g state on ferromagnetism in half-metallic ZnO:Fe

Abstract

Based on first principle calculations using GGA + U approach, we have studied the origin of room-temperature ferromagnetism in Fe-doped ZnO. The ferromagnetic coupling and the contribution of Fe-d states on the ferromagnetism of ZnO are also studied. The p–d exchange interaction between the Fe-d and O-p states is responsible for the ferromagnetism at lower Fe concentration in ZnO; whereas at the higher concentration, the enhanced short-range antiferromagnetic coupling between Fe ions dominates over ferromagnetism. The DOS results depict that the Fe-dt2g state predominantly contributes the hybridization at the fermi level resulting the magnetism in the Fe-doped ZnO system. The total energy calculations reveal the existence of short-range ferromagnetic coupling in the system. The band structure results depict the half-metallic character of the system with spin-polarized nature.