Influence of epitaxial properties on the mutual inductance response of high-quality YBCO thin films

Abstract

High-quality YBa 2Cu 3O 7− x films have been produced on SrTiO 3 (001) and NdGaO 3 (001) substrates. X-ray Φ scans show a good in-plane texture but do not exclude the presence of domains at 90°. Diamagnetic shielding properties obtained from mutual-inductance measurements show a double peak structure which may be ascribed to the presence of those domains. This point is further supported with an analysis of the normal-state resistivity. Films with an interdomain resistivity of 10 −5 Ω cm show a double peak structure in the mutual-inductance measurements and relatively low values of the critical current densities (1.5 × 10 5 A cm −2 at 77 K), while films with interdomain resistivities lower than 10 −6 Ω cm show a narrow single peak and higher values of the critical current (10 6 A cm −2 at 77 K).