High Tc Y-Ba-Cu-O thin films prepared by in situ low-temperature codeposition of Y, BaF2, and Cu on α-Al2O3 substrates

Thin Y-Ba-CU-O films were prepared in-situ by low-temperature codeposition on Al2O3 substrates. The temperatures during preparation did not exceed 600 degree C. As a source of Ba the BaF2 was used. The zero resistance Tc values were higher than 84 K, Jc =4x104 A/cm2 at 4.2 K/OT. The Auger electron spectroscopy analysis has shown almost a homogeneous distribution of the film components throughout the film thickness. X-ray diffraction revealed the presence of unoriented 1-2-3 phase besides BaF2 and CuO and, one undefined phase, which might be oxyfluoride compound