Surface study of YBa2Cu3O7−δ epitaxial films cleaned by an atomic oxygen beam
- 9 May 1994
- journal article
- research article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 64 (19), 2581-2583
- https://doi.org/10.1063/1.111532
Abstract
An atomic oxygen beam generated by a microwave plasma source has been used to clean the surface of high‐Tc superconducting a‐ and c‐axis oriented YBa2Cu3O7−δ (YBCO) epitaxial thin films. The crystallinity and electronic structure of the cleaned films have been characterized in situ using reflection high energy electron diffraction, low energy electron diffraction (LEED), and ultraviolet and x‐ray photoemission spectroscopies (UPS, XPS). Exposure of the surface at 350 °C to the atomic oxygen beam yields sharp LEED spots and a metallic feature at the Fermi level. For a‐axis films, clear LEED patterns and a Fermi edge in UPS spectra of a recleaned surface are simultaneously observed. The contact resistance between a cleaned a‐axis YBCO film and in situ deposited gold was found to be in the range of 10−10–10−9 Ω cm2.Keywords
This publication has 15 references indexed in Scilit:
- In situ Ag/ contacts for superconductor–normal-metal–superconductor devicesPhysical Review B, 1992
- Valence band and Ba core level study of chemically-etched YBa2Cu3O7-δJournal of Electron Spectroscopy and Related Phenomena, 1991
- Low-energy ion scattering spectroscopy observations of c-axis-oriented YBa2Cu3O7−x thin films: Effects of in-vacuum annealingApplied Physics Letters, 1991
- Anomalous interface resistance between oxide superconductors and noble metalsPhysica B: Condensed Matter, 1990
- Surface layers on superconducting Y-Ba-Cu-O films studied with x-ray photoelectron spectroscopyJournal of Applied Physics, 1990
- Reaction of nonaqueous halogen solutions with YBa2Cu3O7−xJournal of Applied Physics, 1989
- Gold contacts on superconducting crystals of YBa2Cu3O7 with very low contact resistivityApplied Physics Letters, 1989
- Angle-resolved photoemission from epitaxialfilmsPhysical Review B, 1989
- High performance silver ohmic contacts to YBa2Cu3O6+x superconductorsApplied Physics Letters, 1988
- HIGH-ENERGY SPECTROSCOPIES AND HIGH-TcSUPERCONDUCTORS : AN OVERVIEWLe Journal de Physique Colloques, 1987