Type-I clathrate Ba8NixSi46-x: Phase relations, crystal chemistry and thermoelectric properties

被引：22

作者：

Falmbigl, M. ^{[1
]}

Chen, M. X. ^{[1
,2
]}

Grytsiv, A. ^{[1
]}

Rogl, P. ^{[1
]}

Royanian, E. ^{[3
]}

Michor, H. ^{[3
]}

Bauer, E. ^{[3
]}

Podloucky, R. ^{[1
,2
]}

Giester, G. ^{[4
]}

机构：

[1] Univ Vienna, Inst Phys Chem, A-1090 Vienna, Austria

[2] Univ Vienna, Ctr Computat Mat Sci, A-1090 Vienna, Austria

[3] TU Vienna, Inst Solid State Phys, A-1040 Vienna, Austria

[4] Univ Vienna, Inst Mineral & Crystallog, A-1090 Vienna, Austria

来源：

DALTON TRANSACTIONS | 2012年 / 41卷 / 29期

关键词：

TOTAL-ENERGY CALCULATIONS; PHYSICAL-PROPERTIES; EQUILIBRIA;

D O I：

10.1039/c2dt30279a

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

The phase relations, crystal structure and thermoelectric properties of the type-I solid solution Ba8NixSi46-x were investigated. Based on X-ray diffraction, differential thermal analysis and electron probe microanalysis data, a partial phase diagram was constructed for the Si-rich part of ternary system Ba-Ni-Si at 800 degrees C. The solubility range of Ni in the clathrate-I phase at 800 degrees C was determined (2.9 <= x <= 3.8) and thermoelectric properties, namely electrical resistivity, Seebeck-coefficient and thermal conductivity, were measured in the temperature range from 300 to 850 K. A shift of the thermoelectric properties from a predominantly metallic to a more semiconducting behavior was observed for an increasing Ni-content. Density functional calculations revealed a significant decrease of the gap width in the density of states induced by the incorporation of Ni. Electrical resistivity and Seebeck coefficients for Ba8NixSi46-x with 3.3 <= x <= 3.8 have been modeled within the rigid band approximation.

引用

页码：8839 / 8849

页数：11

共 48 条

[11] Estimation of the thermal band gap of a semiconductor from Seebeck measurements [J].