Transport in reversibly laser-modified YBa2Cu3O/sub 7-//sub x/ superconducting thin films

A focused argon ion laser beam in a controlled ambient is used to modify the transport properties of superconducting YBa2Cu3O/sub 7-//sub x/ thin films. The laser-modified region shows a sharp transition temperature (T/sub c/≅76 K) that is reduced from the unmodified regions of the film (T/sub c/≅87 K). In situ monitoring of the room-temperature electrical resistance is used to control the laser processing and prevent formation of the semiconducting phase. The original properties of the superconducting film can be recovered by plasma oxidation indicating that the laser-induced phase is oxygen deficient