Synthesis, structure, and high-temperature thermoelectric properties of boron-doped Ba8Al14Si31 clathrate I phases

被引：43

作者：

Condron, Cathie L.

Kauzlarich, Susan M.

Ikeda, Teruyuki ^{[1
,2
]}

Snyder, G. Jeffrey ^{[1
,2
]}

Haarmann, Frank ^{[3
]}

Jeglic, Peter ^{[3
]}

机构：

[1] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA

[2] CALTECH, Pasadena, CA 91125 USA

[3] Max Planck Inst Chem Phys Fester Stoffe, D-01187 Dresden, Germany

来源：

INORGANIC CHEMISTRY | 2008年 / 47卷 / 18期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1021/ic800772m

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

Single crystals of boron-doped Ba(8)Al(14)Si(31) clathrate I phase were prepared using Al flux growth. The structure and elemental composition of the samples were characterized by single-crystal and powder X-ray diffraction; elemental analysis; and multinuclear (21)Al, (11)B, and (29)Si solid-state NMR. The samples' compositions of Ba(8)B(0.17)Al(14)Si(31), Ba(8)B(0.19)Al(15)Si(31), and Ba(8)B(0.32)Al(14)Si(31) were consistent with the framework-deficient clathrate I structure Ba8Al(x)Si(42-3/4x)square(4-1/4x) (X = 14, square = lattice defect). Solid-state NMR provides further evidence for boron doped into the framework structure. Temperature-dependent resistivity indicates metallic behavior, and the negative Seebeck coefficient indicates that transport processes are dominated by electrons. Thermal conductivity is low, but not significantly lower than that observed in the undoped Ba(8)Al(14)Si(31) prepared in the same manner.

引用

页码：8204 / 8212

页数：9

共 35 条

[1]

Blake N. P., 2002, J CHEM PHYS, V116, P9545

[2] Why clathrates are good thermoelectrics:: A theoretical study of Sr8Ga16Ge30 [J].