Electronic Structure of Vanadium Oxide Clusters in Layered Perovskite Compounds Sr_n+1V_nO_3n+1 (n=1, 2, 3)

抄録

The electronic structures of layered-perovskite oxides Sr_n+1V_nO_3n+1(n=1, 2, 3) have been analyzed through ab initio molecular-orbital calculations for VO₆ clusters, using the Hartree-Fock method followed by Møller-Plesset perturbation and configuration-interaction corrections. Comparisons of the electronic states have been made among VO₆, CuO₆ and CuO₄ clusters to study the possibility of realizing vanadate superconductors on the analogy of the high-T_c cuprate superconductors. Hole- and electron-doped states have also been investigated as well as the undoped state. We thus clarify a number of similarities and differences between the vanadates and the cuprates. It is also suggested that some of these differences may prevent the layered vanadium oxides from becoming high-T_c superconductors.