Effects of Nb impurity on orthorhombic PbZrO3 crystals

Abstract

A study of Nb doping in lead zirconate (PbZrO3) has been carried out by using a quantum-chemical method developed for crystals and a periodic supercell model. One of the Zr atoms was replaced by an Nb atom in the supercell consisting of 80 atoms. The obtained geometry optimization for the defective region points to defect-outward atomic movements, which are accompanied by some reduction of atomic charges. It is observed that an extra electron imposed by the Nb impurity is transferred to the conduction band of the material and contributes to the n-type electrical conductivity, explaining indirectly some of the experimental observations. © 2008 The Royal Swedish Academy of Sciences.