ELECTRONIC-STRUCTURE OF THE BAN+1PBNO3N+1 HOMOLOGOUS SERIES

A combination of linear augmented-plane-wave and tight-binding (TB) techniques has been applied to calculate the electronic band structures of selected members of the Ban+1PbnO3n+1 ho- mologous series. The results show that the two end members of this series, Ba2PbO4 (n=1) and BaPbO3 (n=), exhibit semiconducting and metallic properties, respectively. The calculated (1.7 eV) semiconductor gap in Ba2PbO4, which has the K2NiF4-type structure, is due to nearest-neighbor (sp) interactions between Pb(6s) and O(2p) orbitals at the apical sites. TB calculations for intermediate members of this series show that this gap vanishes for the n=3 phase, Ba4Pb3O10, yielding semimetallic behavior. A detailed analysis of the electronic properties of this system suggests related compounds that are promising candidates for high-temperature superconductivity. © 1990 The American Physical Society.