Electronic Structure of Perovskite Oxides, LaMO3 (M = Ti-Ni), from High-Energy Electron Spectroscopic Investigations

We study the electronic structure of the LaMO3 (M = Ti-Ni) perovskite oxides as probed by various high-energy electron spectroscopics. These spectroscopic studies, in conjunction with model many-body calculations, provide important information concerning the ground state character of these oxides. In particular, the on-site Coulomb interaction strength, Udd, the charge transfer energy, Δ, and the transfer integral between the metal 3d and oxygen 2p states, t , have been estimated. These parameters are found to exhibit a systematic variation across the series. Electronic structure of the perovskites is discussed in terms of electron-removal and electron-addition spectra for the parent compound as well as for doped LaMO3, with specific reference to semiconductor-metal transitions.