The thermal conductivity of a high-conductivity single crystal was measured between 0.7 and 30K (figure 3). A marked feature of the observed temperature dependence was a non-linear behaviour of the thermal conductivity at the lowest temperatures, where a linear dependence was expected. Additional measurements of electrical conductivity in a magnetic field showed that the non-linearity originated from a scattering mechanism which led to a decrease in the electronic component of the thermal conductivity.

Thermal Conductivity of LaB6: the Role of Phonons. Flachbart, K., Reiffers, M., Molokáč, Š., Belling, A., Bischof, J., Konovalova, E., Paderno, Y.: Physica B, 1999, 263-264, 749-51

Figure 3

Thermal Conductivity as a Function of Temperature