Pulsed laser deposition synthesis of superconducting (Cu, C)Ba2CuOx thin films

(Cu, C)–Ba–O thin films have been deposited at low growth temperature of 450–570°C by pulsed laser deposition method. A control of CO2 gas pressure and the growth temperature, usage of BaCuyOx pellet target resulted in an expansion of twice c-axis length of BaCuO2 structure (2c phase) and a significant rise of conductivity. Measurements of in-situ XPS suggest that the 2c phase should be (Cu, C)Ba2CuOx [(Cu, C)-1201]. The maximum temperature of onset of the superconducting transition and zero resistance state obtained so far were 60 and 47K, respectively.