Influence of the grain boundary network on the critical current ofYBa2Cu3O7films grown on biaxially textured metallic substrates

Abstract

YBa 2 Cu 3 O 7 /YSZ/CeO 2 heterostructures have been grown epitaxially on biaxially textured Ni substrates by pulsed laser deposition. The texture of the film was determined by electron backscattering diffraction, providing information on the propagation of the grain boundary network from the Ni substrate to the YBa 2 Cu 3 O 7 film via the epitaxial growth. The grain boundary network limits the critical current density to 0.3 MA/cm 2 (77 K, 0 T), compared with 1.3 MA/cm 2 (77 K, 0 T) for a film grown on a single crystalline Ni substrate. Transport measurements on the coated conductor sample at different temperatures and magnetic fields show that there is a crossover field between intergrain and intragrain critical current that is shifted to higher magnetic fields as the temperature is reduced.