Effects of filling atoms Ba, Ce, Y and substituting atoms Fe, Ni on lattice thermal conductivity of R_yM_xCo_{4 - X}Sb ₁₂

Effects of filling atoms with different ionic radiuses Ba, Ce, Y and different substituting atoms Fe, Ni on the lattice thermal conductivity of filled R_yM_xCo_{4 - x}Sb₁₂ are systematically studied. The results show that the lattice thermal conductivity decreases significantly by filling Ba, Ce, Y atoms in Sb-icosahedron voids, and the reducing range of the lattice thermal conductivity increases with the ionic radii of Ba²⁺, Ce³⁺ and Y³⁺ decreasing. The lowest lattice thermal conductivity and strongest rattling actions of filling atoms on scattering of phonons are obtained when the Sb-icosahedron voids are partly filled. The lattice thermal conductivity of R_yM _xCo_{4 - x}Sb₁₂ decreases greatly by substituting Co with Fe or Ni, and the substituting atoms Ni are more effective than Fe in reducing lattice thermal conductivity.