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利用高压(2~5GPa)固相反应法合成了单相的方钴矿多晶体化合物Co4Sb12-xSex(0≤x≤1.2).室温下对其电阻率(ρ),Seebeck系数(S)以及微观形貌(SEM)进行了测试分析.结果表明,高压固相反应法合成的样品Co4Sb12-xSex具有细小的晶粒和大量的晶界,晶粒直径处于微纳米级.样品的Seebeck系数绝对值随Se置换浓度(x)而增大,电阻率随Se置换浓度x的升高而显著增大.在合成压强为4.25GPa时,样品Co4Sb10.8Se1.2具有绝对值最大的Seebeck系数501.59μV/K,Co4Sb11.9Se0.1获得最大的功率因子值为3.77μW/cm·K2. 相似文献
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Phase compositions, morphologies and hydrogen storage properties of the as-cast and copper-mould-cast LaMgaNi alloys were studied. The dehydriding onset temperature of the as-cast alloy hydride was about 500 K, which was at least 50 K higher than that of the copper-mould-cast one, and the copper-mould-cast alloy hydride had a faster dehydriding rate compared with as-cast one. Additionally, the copper-mould-cast alloy could uptake 2.85 wt.% hydrogen, which was 95.0% of saturated hydrogen storage capac- ity at room temperature. While only 1.80 wt.% hydrogen (60% of saturated capacity) was absorbed for the as-cast alloy under the same conditions. The reversible hydrogen storage capacities and plateau hydrogen pressures of the two alloys were close. X-ray dif- fractions and scanning electron microscopy results indicated that similar thermodynamic property of the two alloys should be ascribed to the same hydrogen storage phase, Mg and MgzNi. The better hydrogen sorption kinetics of copper-mould-cast alloy should be as- cribed to the more uniform phase distribution compared with that of the as-cast one. 相似文献
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利用一步高压烧结方法制备了CoSbS_(1-x)Se_x基固溶体合金,测试并分析了其结构和热电性能。结果表明,高压能够加快反应速率,快速制备出单相CoSbS化合物;加入少量Se能够同步优化3个热电参数:即提高Seebeck系数,降低电阻率和热导率。在673 K时,CoSbS_(0.8)Se_(0.2)具有最大的品质因子ZT~0.25,约为母体材料CoSbS的4倍,而且在相同温度条件下高压合成样品的ZT远高于传统方法(固相反应结合放电等离子体烧结)制备CoSbS_(1-x)Se_x的数值。这些结果表明,高压方法是制备CoSbS基热电材料的一种有效方法。 相似文献