Synthesis of Y-Ba-Cu-O Thin Films on Sapphire Substrates by RF Magnetron Sputtering

Y-Ba-Cu-O thin films have been prepared on sapphire substrates by RF magnetron sputtering from sintered targets. The substrate temperature dependence of Ba and Cu concentrations against Y of as-sputtered films has been clarified. Film composition deviated from target composition. Cu concentration decreased significantly with increasing T_s, while Ba concentration was independent of the substrate temperature. Using the CuO-compensated Y₁Ba₆Cu₁₀O_x target, assputtered high-T_c films (T_c onset=87 K, T_c endpoint=40 K) have been successfully obtained as a T_s of about 580°C.