Magnetic coupling properties of Zn vacancies in ZnO nanowire with screw dislocation

Abstract

The electronic structure and magnetic coupling property of Zn vacancy (VZn) in ZnO nanowires (ZnONWs) with screw dislocations were investigated using first-principle calculation based on density functional theory (DFT). The optimized configuration of the screw dislocation shows that all of the atoms in dislocation cores are 3-fold coordination, favoring the formation of VZn. These VZn are ferromagnetic, which is achieved by spin polarization of the surrounding 3-fold coordination O atoms. Furthermore, the periodicity of the screw dislocations along [0001] direction can facilitate the aggregation and interaction of VZn. As a result, the p-p coupling between O atoms around VZn is continuous along [0001], which leads to long range ferromagnetism (FM) ordering of the system. Also, the dislocations can capture carriers, which realize the control of magnetic moment.