Thermal conductivity of T 12 Ba 2 Ca 2 Cu 3010 ceramics from 300 K down to 0 . 1

Thermal conductivity, K, of two ceramic samples of T12Ba2Ca2Cus0,c has been measured over a ten-Zerature range from 300 K down to 0.1 K. At high temperatures, the data show features similar to the thermal conductivity of Y-Ba-Cu-0 and Bi-Sr-CaCu-0 ceramics in both the magnitude and the temperature dependence. Specifically, a sudden increase in the thermal conductivity is observed at the onset of a superconducting transition near 120 K culminating in a pronounced maximum of K around 75 K and an eventual rapid decrease of the thermal conductivity at lower temperatures. From 5 K down to 0.1 K we observe the thermal conductivity to decrease with an average power law exponent between 2.4 and 2.5. Such a temperature dependence is comparable with that for sintered Bi-Sr-Ca-Cu-0 samples, but differs from the quadratic variation typical for Bi-Sr-Ca-Cu-0 single crystals and the T-linear asymptotic behavior characteristic of Y-Ba-Cu-0 and La-Sr-Cu-0 ceramics.