The surface characterization and the stability of high-temperature superconductor

A surface characterization of the ceramic superconductor was performed by means of Auger electron spectroscopic, x-ray photoelectron spectroscopic and sputtered neutral-particle mass spectroscopic analyses. Results of our analyses indicate that there are some Pb-enriched regions formed on the surface layer of the superconductor. Together with the Hg deposition on the surface of the ceramic sample, the Pb-enriched regions behave as clustering defect structures. They probably play the role of flux pinning centres to resist the flux creep.