Lattice thermal conductivity of R_yM_xCo_4-xSb₁₂

The effects of filling atoms with different ionic radii of Ba, Ce, Y and different substituting atoms Fe, Ni on the lattice thermal conductivity of filled R_yM_xCo_4-xSb₁₂ are investigated. The results show that the lattice thermal conductivity decreases significantly when Ba, Ce, Y atoms filled in Sb-icosahedron voids, and the reducing range of the lattice thermal conductivity increases in the order of decreasing ionic radius of Ba, Ce and Y. The lowest lattice thermal conductivity and strongest rattling actions of filling atoms to the scattering of phonons are gained when the Sb-icosahedron voids are partly filled. The lattice thermal conductivity of R_yM_xCo_4-xSb₁₂ decreases greatly by substituting Fe or Ni for Co, and the substituting atoms Ni are more effective than Fe.