Magneto-transport characterization of Dy 123 monodomain superconductors

摘要

We consider textured materials of the DyBa_2Cu_3O_7 type seeded with a Nd123 seed as initiator. They are grown with an excess 20% Dy211 phase on a Dy_2O_3 substrate. We report chemical characterization, electrical resistivity, thermoelectric power and thermal conductivity over a broad temperature range as a function of an applied magnetic field up to 6 T. We show that specific features appear in the magneto-thermal transport properties, different in these materials from those found in single crystals and polycrystalline samples. We propose that two vortex regimes can be distinguished in the mixed phase, due to the intrinsic microstructure. We calculate the viscosity, entropy and figure of merit of the samples.