YBCO thin film preparation on unbuffered Ag substrate by resistive evaporation

It is widely accepted that thin film formation of YBCO on conducting and fl exible substrate is one of the keys for further development of advanced dev ices in the microelectronics. Various fabrication methods such as spray pyr olysis, powder-in-cube processing, dip-coating rolling-assisted biaxially. textured substrate, etc., widely used for YPBCO thick films (few tens of mu m) production. However in this work we report for the first time on the pr eparation of YBCO thin film on unbuffered silver substrate using a simple c onventional vacuum system equipped with only one single resistively heated evaporation source. The subsequent heat treatment was carried out under a l ow oxygen partial pressure and temperature that never exceeded 740 degrees C. A thin film of Ag was first deposited on MgO substrate. A pulverized sto ichiometric mixture of Y, Cu, and BaF2 was then deposited on this film. The amorphous YBCO film of a 500-nm thickness was obtained after the heat trea tment. The results of the film evaluation are presented and discussed.