摘要
Non-stoichiometric samarium monosulfide（SmS_x, 0.55≤x≤1.2） was synthesized from Sm_2S_3 and SmH_3 at 1273 K for 3 h under vacuum. The influence of reaction ratio of Sm_2S_3 to SmH_3 on the fabrication of SmS_x was investigated. The fabrication of SmS required the molar ratio of Sm_2S_3 to SmH_3 above 1. Lattice parameter of synthetic SmS_x increased firstly and then decreased to saturate following with the addition of SmH_3 content. SmS_x compact was sintered at 1373 K by spark plasma sintering. Density of synthetic SmS_x was about 99% of theory density. Seebeck coefficient of n-type semiconductor Sm Sx decreased as temperature rose. The absolute value was distributed between 170–280 μV/K. The electrical resistivity of SmS_x（0.86≤x≤1.07） decreased with temperature increasing and showed similar temperature dependence. The surplus Sm which randomly distributed in the SmS_x（0.55≤x≤0.75） matrix led to a remarked reduction of electrical resistivity. The optimized power factor for SmS_（0.6） and Sm S_（0.75） could reach 1500 μW/（K^2·m） at 600 K.
Non-stoichiometric samarium monosulfide（SmS_x, 0.55≤x≤1.2） was synthesized from Sm_2S_3 and SmH_3 at 1273 K for 3 h under vacuum. The influence of reaction ratio of Sm_2S_3 to SmH_3 on the fabrication of SmS_x was investigated. The fabrication of SmS required the molar ratio of Sm_2S_3 to SmH_3 above 1. Lattice parameter of synthetic SmS_x increased firstly and then decreased to saturate following with the addition of SmH_3 content. SmS_x compact was sintered at 1373 K by spark plasma sintering. Density of synthetic SmS_x was about 99% of theory density. Seebeck coefficient of n-type semiconductor Sm Sx decreased as temperature rose. The absolute value was distributed between 170–280 μV/K. The electrical resistivity of SmS_x（0.86≤x≤1.07） decreased with temperature increasing and showed similar temperature dependence. The surplus Sm which randomly distributed in the SmS_x（0.55≤x≤0.75） matrix led to a remarked reduction of electrical resistivity. The optimized power factor for SmS_（0.6） and Sm S_（0.75） could reach 1500 μW/（K^2·m） at 600 K.
基金
Project supported by Scientific Research(B)(24360314)from the Ministry of Education,Science,Sports and Culture of Japan
