Influence of film thickness on the critical current of YBa2Cu3O7-x thick films on Ni-V biaxiallytextured substrates

摘要

A promising approach to improve the engineering current density of coated conductors is to increase the thickness of the YBa2Cu 3O7-x (YBCO) layer. In this framework, a study regarding the relationship between the thickness of the superconducting film and its critical current was performed on biaxially aligned YBCO films grown on epitaxial Ce2O/NiO structure using Ni89 V11 non-magnetic substrate. The critical current density (JC) was measured for a series of YBCO films with thickness ranging from 0.2 to 2 μm, deposited at constant rate. JC values up to 6.4×105 A/cm2 at 77 K and zero magnetic field were obtained for thinner films decreasing three orders of magnitude for the 2 μm thick YBCO film. X-ray diffraction and morphological analyses indicate a progressive structural deterioration with the increase of film thickness