Magneto-optical testing of of superconductive homogeneity of large HTS films

The results of investigating the homogeneity of superconductive properties of HTS films of Y1Ba2Cu3O7-σ composition by the method of magnetic flux inhomogeneity visualization are presented. This method relies on the Faraday effect in Bi-containing ferrite-garnet epitaxial films super posed on the surface of HTS films. The analysis of the obtained results shows that critical parameters of HTS films can be enhanced through the application of improved substrates. The method of magneto-optical testing of film homogeneity can be used efficiently for the development of methods of selecting substrate billets and surface machining technology