The Influence of Magnetic Field on Microwave Surface Resistance of Two-Layer YBa sub 2 Cu sub 3 O sub 7-x Films

• Published in: Solid state communications Vol. 84; no. 3; pp. 327 - 332
• Main Authors: Vendik, O G, Kozyrev, A B, Karmanenko, S F, Klimenko, V L, Njakshev, K F, Soldatenkov, O I
• Format: Journal Article
• Language: English
• Published: 01.10.1992
• ISSN: 0038-1098

Using reflection high energy electron diffraction (RHEED) analysis and electron microscopy of YBa sub 2 Cu sub 3 O sub 7-x films prepared by d.c. magnetron sputtering, it has been shown that the films consist of high-oriented and granular layers. The non-monotonous dependence of microwave surface resistance on film thickness confirmed the presence of two layers with different kind of structure into the film with thickness > 300-400 nm. The influence of frozen magnetic flux on microwave surface resistance of high-oriented and two-layer films has been investigated. For a description of microwave response in magnetic field a two-layer model of oxide superconductor film on the basis of classical two-fluid model and the model of granular medium with Josephson intergrain contacts has been proposed. The influence of the granular layer parameters on microwave surface resistance of two-layer films has been determined.