LIQUID-PHASE EPITAXY OF YBA2CU3O7-X ON NDGAO3 AND LAGAO3 SUBSTRATES

Liquid phase epitaxy of YBa2Cu3O7-x films was achieved with NdGaO3 and LaGaO3 substrates at temperatures T = 960-970-degrees-C and deposition times t = 10-45 min in CaO- or Y2O3-stabilized ZrO2 crucibles. Twinned a,b-films with parts of c-orientation were prepared on (110) NdGaO3 substrates and c-films on (001) LaGaO3 substrates; 5-10 mum thick films are cracked. AC susceptibility measurements with "as-grown" a,b-films demonstrate superconductivity at T(onset) almost-equal-to 50 K and a transient of about 10 K. Annealing in oxygen increases T(onset) to 90 K with a transient between 0.5 and 10 K. Ca or Zr impurities could not be detected in the films.