High Pressure Synthesis and Electric Transport Properties of La Filled CoSb3 Skutterudite Thermoelectric Materials
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摘要: 采用高温高压手段,在压力3.5 GPa、温度900 K的条件下,成功合成出La填充型方钴矿热电材料LaxCo4Sb12(0x1.0),系统地研究了样品的晶体结构和电输运性能随填充分数x的变化关系。研究结果表明:在最大填充分数x为0~1.0的范围内,随着La填充分数的增加,样品的晶胞常数稍有增大,晶体结构仍为典型的方钴矿结构,没有La杂质相出现。室温下样品的电输运性能测试结果表明:La填充型方钴矿为p型半导体;样品的电阻率和Seebeck系数随La含量的增加均呈现出先增加后逐渐降低的趋势;当填充分数x为0.3时,样品的Seebeck系数和电阻率均达到了最大值;功率因子在x=0.5时达到了最大值。Abstract: La-filled skutterudite compounds LaxCo4Sb12 (0<x1.0) were successfully synthesized at 3.5 GPa and 900 K. The X-ray diffraction results indicate that all synthesized samples exist as a single phase with a crystal structure of CoSb3. The composition-dependent electric transport properties of La-filled CoSb3 have been studied at room temperature. The lattice parameters of the samples increase gradually with the increasing of La content. No La phase is found in the range of x from 0.1 to 1.0. The La-filled skutterudite is p type semiconductor. The electrical resistivity and Seebeck coefficient increase firstly with the increasing of La content and then decrease. When the La content x is 0.3, the electrical resistivity and Seebeck coefficient both reach the maximum value. The maximum power factor is obtained when the La content x is 0.5.
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Key words:
- La /
- skutterudite /
- high temperature and high pressure /
- thermoelectric material
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