INFLUENCE OF EPITAXIAL PROPERTIES ON THE MUTUAL INDUCTANCE RESPONSE OF HIGH-QUALITY YBCO THIN-FILMS

High-quality YBa2Cu3O7-x films have been produced on SrTiO3 (001) and NdGaO3 (001) substrates. X-ray Phi scans show a good in-plane texture but do not exclude the presence of domains at 90 degrees. Diamagnetic shielding properties obtained from mutual-inductance measurements show a double peak structure which may be ascribed to the presence of thos e domains. This point is further supported with an analysis of the nor mal-state resistivity. Films with an interdomain resistivity of 10(-5) Omega cm show a double peak structure in the mutual-inductance measur ements and relatively low values of the critical current densities (1. 5 x 10(5) A cm(-2) at 77 K), while films with interdomain resistivitie s lower than 10(-6) Omega cm show a narrow single peak and higher valu es of the critical current (10(6) A cm(-2) at 77 K).