Analysis of infrared - visible - near - ultra violet reflectivity of conducting and superconducting oxides

Abstract : We analyse infrared-visible-near-ultraviolet spectra of oxide materials in the semiconducting or metallic phase. We show that the response of laser-ablated YBa2Cu3O7 film can be fitted by a modified Drude term without mid-infrared absorptions. Mid-infrared and visible absorptions are discussed for textured YBaCuO, BaBiO3 and Pr2NiO4+δ as well as indication of their polaronic origin.