The preparation of superconducting thin films of YBa2Cu3O7−x by CO‐evaporation with electron‐beam/thermal sources

YBa2Cu3O7−x films are produced through a combination electron‐beam/thermal evaporation process. The resistivity behavior and structures of the prepared films are correlated to as‐deposited compositions, annealing temperatures and substrate temperatures. In particular, ‘‘ab’’‐oriented YBa2Cu2O7−x films are observed to grow both on (001) SrTiO3 and (1102) Al2O3. Also, under some conditions, ‘‘c’’‐oriented YBa2Cu3O7−x films are grown on (001) SrTiO3. Plasma oxidation is shown to sharpen the transitions but can produce a resistive foot due to oxidation of non‐stoichiometric compositions at grain boudaries.