The role of Ga in Ba0.30GaxCo4Sb12+x filled skutterudites
The role of Ga in Ba0.30GaxCo4Sb12+x filled skutterudites
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DOI：
10.1039/c2jm31677c
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发表时间：
2012-07
影响因子：
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通讯作者：
X. Su;Han Li;Yonggao Y. Yan;H. Chi;Xinfeng Tang;Qingjie Zhang;C. Uher
中科院分区：
文献类型：
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作者：
X. Su;Han Li;Yonggao Y. Yan;H. Chi;Xinfeng Tang;Qingjie Zhang;C. Uher
采用熔体-淬火-退火- sps法制备了Ba0.30GaxCo4Sb12+x （x = 0-0.30）的角钨矿化合物，研究了Ga含量对结构和热电性能的影响。在Ga含量x≤0.15的样品中，Ga进入了方角石的空洞，它的存在似乎刺激了填料种类的更均匀分布。Ga含量x≥0.20的样品具有均匀分散的纳米包裹体，由直径为20 nm的GaSb圆形畴组成。随着Ga含量的增加，载流子浓度降低，塞贝克系数增大，热输运逐渐受阻。与Ba0.30Co4Sb12相比，ba0.30 ga0.30 co4sb12 +x的热电优值明显增强，在850 K时，Ba0.30Ga0.30Co4Sb12.30的热电优值超过1.35，约为Ba0.30Co4Sb12样品的两倍。
Ba0.30GaxCo4Sb12+x (x = 0–0.30) skutterudite compounds were synthesized using a melt–quench–anneal–SPS method and the effect of the content of Ga on the structure and thermoelectric properties was investigated. In samples with Ga content x ≤ 0.15, Ga enters the skutterudite voids and its presence seems to stimulate a more homogeneous distribution of the filler species. Samples with Ga content x ≥ 0.20 possess uniformly dispersed nanoinclusions consisting of circular domains of GaSb with a diameter of 20 nm. As the content of Ga increases, the carrier concentration decreases, the Seebeck coefficient increases, and the heat transport is progressively more impeded. The thermoelectric figure of merit of Ba0.30GaxCo4Sb12+x is strongly enhanced in comparison to that of Ba0.30Co4Sb12 and reaches values in excess of 1.35 at 850 K for Ba0.30Ga0.30Co4Sb12.30, approximately twice the value of the Ba0.30Co4Sb12 sample.