Electronic structure of Bi2CuO4 with antiferromagnetic spin ordering

Abstract

The electronic structure of antiferromagnetic Bi2CuO4 is calculated by using generalized gradient approximation considering on-site Coulomb interaction between d-electrons (GGA+U). The GGA+U calculation indicates clearly that the antiferromagnetic phase is the stablest among non-magnetic, ferromagnetic and antiferromagnetic phases. By using U parameter (7.48 eV) and J parameter (0.95 eV), the band gap energy of Bi2CuO4 is calculated to be ca. 2.4 eV, which is comparable to the experimental one. The valence band maximum is approximately located at the X-point and the conduction band minimum at the Γ-point. This means that antiferromagnetic Bi 2CuO4 is an indirect energy gap material. The calculated total density of states of Bi2CuO4 well corresponds to the state density experimentally deduced by x-ray photoelectron and electron-energy-loss spectroscopy. Also, it is found from the partial density of states analysis that the top of the valence band is mainly formed by O 2p orbitais, whereas the lower conduction band mainly consists of Cu 3d x2-y2 orbitals. The magnetic moment at Cu sites is calculated to be 0.72 μB, which is close to experimental values. ©2008 The Ceramic Society of Japan. All rights reserved.