Microwave properties of DyBCO monodomain in the mixed state and comparison with other RE-BCO systems

Abstract

"We report on microwave measurements on DyBa(2)Cu(3)O(7-delta), monodomains grown by the top-seeded melt-textured technique. We measured the field increase of the surface resistance R(s)(H) in the a-b plane at 48.3 GHz. Measurements were performed at fixed temperatures in the range 70 K-T(c) with a static magnetic field mu(0)H < 0.8 T parallel to the c-axis. Low field steep increase of the dissipation, typical signature of the presence of weak links, is absent, thus indicating the single-domain behavior of the sample under study. The magnetic field dependence of R(s)(H) is ascribed to the dissipation caused by vortex motion. The analysis of X(s)(H) points to a free-flow regime, thus allowing to obtain the vortex viscosity as a function of temperature. We compare the results with those obtained on RE-BCO systems. In particular, we consider strongly pinned films of YBa(2)Cu(3)O(7-delta) with nanometric BaZrO(3) inclusions. (C) 2011 Elsevier B.V. All rights reserved.