Core and valence level XPS of clean, cleaved single crystal surfaces of YBa₂Cu₃O₇

Single crystal with sharp superconducting transitions were cleaved in ultrahigh vacuum at 300 K. Y, Ba, Cu, O core and valence level photoemission spectra were taken using monochromatized Al Kα(1486.6 eV) radiation. This data includes the first clean and intrinsic XPS spectra of the Y 123 superconductor, as judged by the lack contaminant features and the single featured Ba and Y lines. © 1989.