Thermoelectric Properties and Microstructure of Ba 8 Al 14 Si 31 and EuBa 7 Al 13 Si 33
Thermoelectric Properties and Microstructure of Ba 8 Al 14 Si 31 and EuBa 7 Al 13 Si 33
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Ba 8 Al 14 Si 31 和 EuBa 7 Al 13 Si 33 的热电性能及微观结构
DOI：
10.1021/cm061483u
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发表时间：
2006
影响因子：
8.6
通讯作者：
G. Snyder
中科院分区：
文献类型：
--
作者：
C. Condron;S. Kauzlarich;F. Gascoin;G. Snyder
使用化学计量量的元素的直接反应合成具有建议的化学计量Ba 8Al 16 Si 30和Eu 2Ba 6Al 16 Si 30的I型笼形物相的粉末样品。粉末X射线衍射数据的Rietveld精修与包合物I型结构一致。成分，微观结构和热电性能的测量上热压球团。由微探针数据确定Ba 8Al 16 Si 30样品的化学计量为Ba 8Al 14 Si 31，接近通式Ba 8AlxSi 42 -3/4x[]4- 14 x（x = 14; []，空心正方形表示晶格缺陷）的缺陷骨架固溶体。在稀土取代化合物的情况下，微结构的微探针分析表明，它不是单相的，而是包含多个组分，大多数是一般的笼形物化学计量。主要相具有化学计量EuBa 7Al 13 Si 32。这两个阶段显示导电性典型的重掺杂半导体负塞贝克系数。这...
Powder samples of the type I clathrate phases, with the proposed stoichiometry Ba8Al16Si30 and Eu2Ba6Al16Si30, were synthesized using direct reaction of stoichiometric amounts of the elements. Rietveld refinement of powder X-ray diffraction data is consistent with the clathrate type I structure. Composition, microstructure, and thermoelectric property measurements were made on hot-pressed pellets. Stoichiometry of the Ba8Al16Si30 sample was determined from microprobe data to be Ba8Al14Si31, close to the deficient framework solid solution of the general formula, Ba8AlxSi42-3/4x[]4-1/4x (x = 14; [], open square indicates lattice defect). In the case of the rare-earth-substituted compound, microprobe analysis of the microstructure indicates that it is not single phase, but contains multiple components, most of the general clathrate stoichiometry. The majority phase has the stoichiometry EuBa7Al13Si32. Both phases show conductivity typical of heavily doped semiconductors with negative Seebeck coefficients. Th...