Critical oxygen partial pressure for the “in-situ” preparation of high Tc superconducting thin films

Abstract The critical (molecular) partial pressure for the “in-situ” growth of Y 1 Ba 2 Cu 3 O 7−x and Bi 2 Sr 2 Ca 1 Cu 2 O 8−y thin films has been determined by an electrochemical method over a temperature range from 560 to 820°C. The results indicate that the critical oxygen partial pressure is mainly determined by the stability of the Cu 2+ state with respect to a reduction process.