Different magnetic responses induced by unequal oxygen vacancies in SrIrO3

摘要

Using first-principles calculations, we investigate the effects of two kinds of oxygen defects on the electronic and magnetic properties in SrIrO3 bulk. One is the oxygen defect in IrO2 plane (Ov1) and the other out-of-plane (Ov2). The results show that both oxygen defects enhance the inherent metallicity of the crystal and there is no tendency to achieve the Mott transition. Most surprised, we find that a small out-of-plane magnetic moment along c axis is formed due to the apical tilting of the defective octahedrons induced by the in-plane oxygen defects. While a local and weak ab in-plane ferromagnetic response comes from the out-of-plane defect which destroys the connectivity between adjacent layers and promotes a small in-plane rotation. In addition to the distortion of the defective blocks, the weak ferromagnetic phenomenon is also limited by the concentration of oxygen defects. Our research indicates that non-equivalent oxygen deficiencies exert distinct regulatory roles on the magnetic properties.