Filled skutterudites have been actively studied as potentially useful thermoelectric materials. SmT4P12 (T=Fe, Ru, Os) and LaxCel-xT4P12(T=Ru, Os) (0 ≤ x ≤ O.2) with the filled skutterudite-type structure have been prepared at high temperature and high pressure. The structure of samples was characterized by powder X-ray diffraction. The thermoelectric properties of these compounds have been investigated by means of electrical resistivity, Seebeck coefficient and thermal conductivity measurements. SmFe4P12 and SmOs4P12 behaved metallic down to 5K, while SmRu4P12 shows metal-insulation transition around 16K. SmFe4P12 showed significantly high values of Seebeck coefficient (46μV/K), comparing to other metallic compounds at the temperature 600K. LaxCel-xT4P12 (T=Ru, Os) (0 ≤ x ≤ 0.2) showed semiconducting behavior, and the power factor was optimized by doping 10% La in CeRu4P12.投稿論