Ab initio and photoemission study of correlation effects in SrRuO 3 thin films

Abstract

We present the experimental and theoretical study of correlation effects in epitaxial SrRuO3 thin films. Experimentally, we have performed resonant ultraviolet photoemission spectroscopy (UPS) and angle-resolved hard x-ray photoemission spectroscopy (HAXPES) measurements. For resonant UPS, the two methods, Fano-profile fitting of constant initial state spectra and the energy distribution curves equidistant difference spectra, were used to extract Ru 4d partial spectral weight (PSW) in the valence band. We find Ru 4d PSW possessing a clearly pronounced coherent peak at the Fermi level together with angle-resolved HAXPES spectra demonstrating no difference in surface and bulk electronic structure. From comparison of experimental data with theoretical calculations done at density functional theory level, we conclude that SrRuO3 is a weakly correlated material and electronic structure of it can be consistently described employing first-principles approaches. © 2013 American Physical Society.