Surface states of YBa₂Cu₃O_x studied by X-ray photoelectron spectroscopy (XPS)

Abstract

The surface states of orthorhombic YBa₂Cu₃O_x were examined by XPS. The surface enrichment of Y and Ba was observed with the formation of surface layer, Ba and Y carbonates. The surface Y and Ba concentration decreased with the increase of Ar ion sputtering time, due to the decrease of Ba and Y carbonates. The thickness of surface layer was estimated to be as several nm.