YBA2CU3O7-DELTA FILMS ON GAAS WITH HIGH CRITICAL CURRENT DENSITIES

Epitaxial YBa2Cu3O7-delta films were grown on GaAs substrates using an intermediate MgO buffer layer. It turned out that the basic requireme nts in coping with GaAs related problems such as chemical instability and volatility are lowest possible deposition temperatures and proper encapsulation of bare GaAs faces, respectively. Applying our coevapora tion technique we were able to achieve YBa2Cu3O7-delta films on GaAs w hich can compete with those on standard substrates (T(c) = 87 K, rho(1 00K) = 40muOMEGAcm, j(c) = 2 . 10(6) A/cm2 at 77 K).