Preparation and transport properties of polycrystalline Bi and Bi–SiO2 nanocomposites
Preparation and transport properties of polycrystalline Bi and Bi–SiO2 nanocomposites
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DOI：
10.1063/1.1289079
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发表时间：
2000-08
影响因子：
3.2
通讯作者：
F. Brochin;B. Lenoir;X. Devaux;R. Martin-Lopez;H. Scherrer
中科院分区：
文献类型：
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作者：
F. Brochin;B. Lenoir;X. Devaux;R. Martin-Lopez;H. Scherrer
采用粉末冶金法制备了铋-二氧化硅纳米复合材料和多晶铋，研究了二氧化硅夹杂对铋热电性能的影响。通过电弧等离子体处理制备含有0.5至15体积%二氧化硅的Bi-SiO2粉末和纯Bi粉末。透射电子显微镜的调查显示，存在的纳米二氧化硅壳周围的Bi晶粒。将粉末冷压并在接近铋的熔化温度下烧结。铋和Bi-SiO2纳米复合材料的体微结构是非常不同的，因为二氧化硅，这是主要分散在晶界，抑制烧结过程中的晶粒生长。电阻率从5至300 K进行测量，而热电功率和热导率从65至300 K进行测量的多晶铋和Bi-SiO2样品含有0.5，4，和15体积%的二氧化硅，分别。输运性质主要取决于材料的性质。
Bismuth–silica nanocomposites and polycrystalline bismuth were prepared via powder metallurgy in order to study the influence of silica inclusions on the thermoelectric properties of bismuth. Bi–SiO2 powders containing from 0.5 to 15 vol. % of silica and pure Bi powders were produced by an arc-plasma processing. Transmission electron microscopy investigations revealed the presence of a nanometric silica shell around the Bi grains. The powders were cold pressed and sintered close to the melting temperature of bismuth. The bulk microstructures are very different for the bismuth and the Bi–SiO2 nanocomposites because silica, which is primarily dispersed at grain boundaries, inhibits the grain growth during sintering. The electrical resistivity was measured from 5 to 300 K, while the thermoelectric power and the thermal conductivity were measured from 65 to 300 K on both polycrystalline bismuth and Bi–SiO2 samples containing 0.5, 4, and 15 vol. % of silica, respectively. The transport properties are mainly di...