R_yM_xCo_(4-x)Sb_(12)化合物的晶格热导率

Lattice thermal conductivity of R_yM_xCo_(4-x)Sb_ (12)

系统地研究了离子半径不同的Ba,Ce ,Y作为填充原子及Fe ,Ni作为置换原子对填充化合物RyMxCo4 -xSb1 2 晶格热导率的影响规律 .结果表明 :在skutterudite结构的Sb组成的 2 0面体空洞中 ,Ba ,Ce,Y的填充原子能显著降低其晶格热导率 ,且晶格热导率降低幅度按Ba ,Ce ,Y离子半径减小的顺序而增大 .Sb组成的 2 0面体空洞部分被Ba ,Ce填充时 ,晶格热导率最小 ,填充原子的扰动对声子的散射作用最强 .在Co位置上Fe和Ni的置换 ,能显著地降低RyMxCo4 -xSb1 2 化合物的晶格热导率 ,与Fe相比 ,Ni对晶格热导率的影响更强 .

In this paper, 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-xSb 12 are systematically 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-xSb 12 decreases greatly by substituting Fe or Ni for Co, and the substituting atoms Ni are more effective than Fe.