NATURE OF THE ELECTRONIC STATES IN THE LAYERED PEROVSKITE NONCUPRATE SUPERCONDUCTOR SR2RUO4

Near-edge x-ray-absorption and photoemission spectra of the noncuprate superconductor Sr{sub 2}RuO{sub 4} are presented. Holes close to the Fermi level are determined by Ru 4{ital d}{sub {ital xy}}, 4{ital d}{sub {ital xz}}, and 4{ital d}{sub {ital yz}} antibonding states. The density of the occupied states at the Fermi level derived from photoemission is higher than in the cuprates and these states have predominantly Ru 4{ital d} character. Angle-resolved photoemission yields a width of the occupied part of the conduction bands that is reduced by a factor of 2 in comparison to band-structure calculations. The importance of electron correlations is also evident in the appearance of screened final states in the Ru 3{ital d} core-level spectrum. {copyright} {ital 1996 The American Physical Society.}