TRANSPORT-PROPERTIES OF YBA2CU3O7 - RESISTIVITY, THERMAL-CONDUCTIVITY, THERMOPOWER AND HALL-EFFECT

For the high-T//c superconductor YBa//2Cu//3O//7, we present results on the resistivity, Hall effect, and thermopower for temperatures up to 350 K as well as on the thermal conductivity in the range 0. 2 K less than equivalent to T less than equivalent to 120 K. The Hall coefficient is positive and varies approximately with T** minus **1. The thermopower is very small and sample dependent. These results suggest transport in more than one band. The thermal conductivity indicates dominant phonon heat transport. For the residual resistivity an upper bound, rho //0 less than equivalent to 250 mu OMEGA cm, is deduced. Combining this with published results for the slope of the upper critical field and the penetration depth, we estimate the specific-heat coefficient, 5 less than equivalent to gamma less than 9 mJ/K**2 mole-Cu, and the effective carrier density, 1. 1 multiplied by (times) 10**2**2 cm** minus **3.