Thermal conductivity of BaCo1-xNixS2

Thermal Conductivity κ of BaCo 1- x Ni x S 2 , which has quasi two-dimensional electronic nature and exhibits the Mott transition with varying x , has been measured by using polycrystalline samples. From the detailed consideration of the observed x and temperature dependence of κ, it is found that the phonon system mainly contributes to the heat conduction. The κ- x curve exhibits a significant dip structure at the insulator-metal phase boundary, where strong phonon scattering by the electron system is expected.