Effect of Dopant Concentration on Electronic and Magnetic Properties of Transition Metal-Doped ZrO2

Abstract

Electronic and magnetic properties of the bulk monoclinic phase of pure and doped zirconia (ZrO2) are calculated. Calculations have been performed using density functional theory based Spanish Initiative for Electronic Simulations with Thousands of Atoms (SIESTA) code. We have considered substitutional doping of transition metals (TM) V, Cr, Mn and Fe in zirconia corresponding to concentrations ranging from 3.125 to 25 %. Our results show that Cr, Mn-, and Fe doped oxides are half-metallic and the half-metallicity remains intact on reducing the dopant concentrations. The total magnetic moment is mainly due to d states of TM atoms and small induced magnetic moment exists on other nonmagnetic atoms as well. Also as the oxygen vacancy influences the performance of oxidebased devices, therefore we model the influence of oxygen vacancy on the magnetic moments in pure and doped zirconia. Our results show that pure oxide system remains nonmagnetic even on the introduction of oxygen vacancy whereas magnetic moment values for TM doped oxide changes. In the presence of oxygen vacancy, the total magnetic moment of V-, Cr-, and Mn doped cell increases whereas it decreases for Fe doping. This shows that oxygen vacancy (V O) has a strong influence on the magnetic properties of the doped oxides. The results may be useful for further study on TM doped ZrO2 system.