Anisotropy measurements of a cuboid of nanostructured hydrothermally-prepared Bi0.45Sb1.55Te3

作者：Bhaskar Ankara; Lai Hsin Chang; Liu Yen Liang; Liu Chia Jyi^*

来源：Ceramics International, 2017, 43(18): 17142-17147.

DOI：10.1016/j.ceramint.2017.09.135

• Bi0.45Sb1.55Te3
• Sintering
• X-ray method
• Electron microscopy
• Electrical conductivity
• Thermal conductivity

A cuboid of p-type Bi0.45Sb1.55Te3 is fabricated using hydrothermal synthesis followed by consolidation using cold pressing and evacuated-and-encapsulated sintering in a Pyrex ampoule. Powder x-ray diffraction, electrical resistivity, thermopower, and thermal conductivity measurements are performed on three different faces of the cuboid, one face perpendicular to the press direction and the other two faces parallel to the press direction. Both the electrical resistivity and thermal conductivity are anisotropic, while the thermopower is nearly isotropic. According to the x-ray diffraction patterns, there are more ab planes oriented within the two faces of the cuboid parallel to the press direction than that of the face perpendicular to the press direction. As a result, the power factor and dimensionless thermoelectric figure of merit zT for the former are larger than for the latter. The magnitude of zT at 300 K for the two faces parallel to the press direction is 1.59 and 1.49, respectively. The magnitude of zT at 300 K for the face perpendicular to the press direction is 1.11.

• 出版日期2017-12-15