Influence of sequential etching on YBCO films deposited by PLD from a nanostructured target

: Huhtinen H, Raittila J, Paturi P, Huhtala VP, Mattila S, Salminen J

Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

: 2003

IEEE Transactions on Applied Superconductivity

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY

: IEEE T APPL SUPERCON

: 13

: 2

: 2777

: 2780

: 4

: 1051-8223

DOI: https://doi.org/10.1109/TASC.2003.812005

Thin YBa2Cu3O6+x (YBCO) films with T-c = 90 K and high critical current in the order of 10(7) A/cm(2) at 77 K are prepared with pulsed laser deposition from a nanostructured target. Changes in the superconducting and structural properties of the films are investigated after repeated thinning by Ar-ion sputtering or by electrochemical etching. As shown by Auger depth profiling, the chemical composition is preserved through the film during Ar-ion sputtering while electrochemical etching changes the atomic concentrations and surface structures. Investigations by SQUID magnetometry and by conventional resistivity measurements give evidence that the dependence of T-c on the film thickness is similar to as-prepared ultrathin films. The thickness dependence of J(c) indicates an excess of pinning centers on the surface of the as-deposited film.