Reversible Tc Change in Bi-Sr-Ca-Cu-O Thin Films by UV Photo and Thermal Annealings

Abstract
UV light irradiation in oxygen atmosphere was found to cause a change of critical temperature in Bi-Sr-Ca-Cu-O thin films. The change was observed to be reversible between 80 K after thermal annealing and 60 K after photo irradiation. It accompanied a change in the lattice constant, suggesting that further oxygen incorporation into the 80 K phase thin films occurred by the UV light irradiation.