Study Of The Correlations Between The Critical Current-Density And The Structures Of Yba2cu3o7-Delta Thin-Films

We examine YBa2Cu3O7-delta thin films grown by DC magnetron sputtering on SrTiO3 substrates by using x-ray double crystal diffraction, x-ray topography and SEM, etc. Various microstructural and compositional parameters of the specimens with higher and lower critical current density (J(c)) are compared. It is found that the J(c) is closely correlated to the structural perfectness, the compositional uniformity and the grain orientation of the films. There is some evidence to show that the intrinsic and surface quality of the substrates influences the quality of the thin films. An optimum procedure for the surface polishing of SrTiO3 substrates is proposed. In addition, a remarkable influence of the growth procedure on the quality of the thin films is also reported.