Thermal conductivity, thermal diffusivity and thermoelectric power of Sm-based bulk superconductors

Abstract

The ab-plane thermal conductivity /spl kappa//sub ab/(T), thermal diffusivity /spl alpha//sub ab/(T) and thermoelectric power S/sub ab/(T) were measured for the highly-oriented Ag-doped superconducting materials Sm/sub 1+2x/Ba/sub 2+x/Cu/sub 3+x/O/sub 7+5x/ (X = 0.1 /spl sim/ 0.4) prepared by a melt process. The absolute value of /spl kappa//sub ab/ and its characteristic enhancement below T/sub c/ were suppressed with increasing content X of the Sm/sub 2/BaCuO/sub 5/ (Sm211) secondary phase, while they were enhanced with increasing content of doped-Ag. The application of the magnetic field up to 10 T clarified that the phonon scattering by vortices was most enhanced with the applied field perpendicular to the ab-plane. The trapped magnetic field also seriously suppressed the /spl kappa//sub ab/(T) enhancement.