Microwave properties of high-temperature superconducting YBCO(BZO) thin films with admixture nano-particles

It was shown that addition of an admixture phase BZO (or any other dielectric phase, e.g., BaSnO₃ (BSO) or Y₂O₃) to “pure” YBCO thin films creates an additional defect nanostructure within the films. This is in agreement with similar results of other research groups (see, e.g., Ref [8]). This defect nanostructure is formed by nano-sized particles of admixture phase, which play the role of strong point-like pinning centers for Abrikosov vortices, as well as columnar defects, which in turn result from the self-organization of the nanoparticles into linear structures (directed primarily along the c axis) and additional dislocations in the film material, generated by these nanoparticles.