Magnetic and electronic properties of 3d transition-metal-doped In₂O₃: An ab initio study

¹  Condensed Matter Theory Group, Department of Physics, Uppsala University Box 530, S-751 21, Uppsala, Sweden, EU
²  Applied Materials Physics, Department of Materials Science and Engineering, Royal Institute of Technology S-100 44, Stockholm, Sweden, EU

Received: 2 June 2009
Accepted: 16 July 2009

Abstract

The magnetic and electronic properties of the transition metal (TM) (V, Cr, Mn, Fe, Co, Ni, Cu) doped In₂O₃ have been theoretically studied by using the density functional theory. When two TM ions are placed close to each other (TM-TM distance of about 3.4 Å), the ferromagnetic ordering is found to be the lowest-energy configuration. The only exception is Fe, which possesses a half-filled band. However, for further separation distance of about 7.2 Å, only Co, Ni and Cu ions (having more than half-filled band) still prefer the ferromagnetic orientation, while V, Cr, or Mn ions (having less than half-filled band) prefer antiferromagnetic ordering. The energies of the band for TM ions show a decrease with increasing TM atomic number. For V, Cr and Mn, the bands are merged with the conduction band, and show less hybridization with the host valence band; while for Co, Ni and Cu, the bands show strong hybridization with the host valence band mainly formed by the oxygen state. In this situation, polarized holes are formed on the oxygen sites close to the TM ions. Moreover, V-doped In₂O₃ is found to meet the requirements for a strong donor-mediated ferromagnetism.