Chemi-physical diagnosis of BiSrCaCuO thin film preparation

Thin film and bulk formation of the new high T/sub c/ superconductive oxide BiSrCaCuO (BSCCO) and related crystal structures has been investigated, emphasizing the beneficial effect of Mg addition on the superconductivity. The onset temperature of the high T/sub c/ phase was raised by a few degrees, and a T/sub c/ (zero) higher than 100 K was easy to obtain in the BiSrCaMgCuO system. The as-grown BSCCO thin film formation is also considered. Sputter-deposited to 48 K without using postanneal. After the film was subjected to the furnace anneal, T/sub c/ (zero) rose to 90 K, though most of the resistance dropped at even higher temperatures. The structural change and chemical shift introduced during the postanneal have been closely examined, showing that sensitivity of the BSCCO crystallinity to the substrate material, annealing time, and temperatures. These characteristic features seem substantially different from those of YBCO system.<>