Remarkable properties of Tl-Ba-Ca-Cu-O thin films following post-growth high-temperature annealing

Tl-2212 and Tl-1212 are the two easiest unsubstituted Tl-Ba-Ca-Cu-O superco nducting thin films to grow, Both phases exhibit T-c greater than or equal to 95 K, J(c)(5K) > 10 MA/cm(2) and smooth morphologies, We report on the p roperties of both materials following one hour furnace anneals in dry ambie nts of pure oxygen or nitrogen at temperatures ranging from 50 - 700 degree s C, The stability of these films to high temperatures in each ambient is i mportant for device processing. Of equal interest is the controlled partial volatilization of Tl-oxide at modest temperatures from nano-size regions w ithin Tl-1212 films. We correlate such modifications with increases in flux pinning strength in Tl-1212 films. Tl-2212 films maintain their supercondu cting properties to even higher temperatures than Tl-1212 films. Optimum an nealing appears to also increase flux pinning, although not to the same deg ree as for Tl-1212 films.