Electronic structure of ARuO(3) (A = Ca, Sr and Ba) compounds

X-ray Photoelectron Spectroscopy (XPS) and Ultraviolet Photoelectron Spectr oscopy (UPS) techniques along with the Tight Binding Linear Muffin Tin Orbi tals within Atomic Sphere Approximation (TB-LMTO-ASA) calculations have bee n used to obtain the electronic structure of ARuO(3) (A = Ca,Sr and Ba) com pounds. Structure of these compounds was refined using Rietveld fitting of the XRD data. (Ca,Sr)RuO3 belong to orthorhombic perovskite oxides whereas BaRuO3 belongs to complex hexagonal perovskite oxides. Structural data indi cated strong Ru-Ru interactions in BaRuO3 whereas no such indication in (Ca ,Sr)RuO3. UPS data show some structures in the conduction bands of (Ca,Sr)R uO3 and show a flat, free electron like conduction band for BaRuO3. UPS and LMTO data indicated a progressive increase in electron correlation strengt h in the series BaRuO3-SrRuO3-CaRuO3. (C) 2001 Elsevier Science Ltd. All ri ghts reserved.