N-type Ba0.3Ni0.15Co3.85Sb12 skutterudite: High pressure processing technique and thermoelectric properties

作者：Kong, Lingjiao; Jia, Xiaopeng; Zhang, Yuewen; Sun, Bing; Liu, Binwu; Liu, Haiqiang; Wang, Chunxiao; Liu, Baomin; Chen, Jiaxiang; Ma, Hongan^*

来源：Journal of Alloys and Compounds, 2018, 734: 36-42.

DOI：10.1016/j.jallcom.2017.11.030

• Thermoelectric
• High pressure
• CoSb3
• Vortices-like structures
• Ba filling

In this letter, Ni substitution for Co and Ba filling into the voids were simultaneously applied to the CoSb3 bulks by the high pressure and high temperature (HPHT) method. As the results, the polycrystalline Ba0.3Ni0.15Co3.85Sb12 skutterudite bulks were successfully synthesized and the systematic thermoelectric properties were investigated. In our experiments, the synthesized time was sharply shortened to 30 min, which is markedly an advantage for mass production. The multiple textures and microstructures were revealed, including vortices-like structures, defects, and lattice dislocations. Remarkably, pressure tuning led to the increase of the Seebeck coefficient and electrical resistivity, yielding an optimized power factor of 11.7 x 10(-4) Wm(-1)K(-2) in the Ba0.3Ni0.15Co3.85Sb12 sample prepared at 3 GPa at room temperature, which yielded a 10-fold improvement in power factor and showed distinct reduction of thermal conductivity compared with pure CoSb3 sample. The maximum zT value 0.91 was obtained at 700 K for Ba0.3Ni0.15Co3.85Sb12 sample. The experimental results suggest that the effective elements doping combining with HPHT synthesis could optimize electrical and thermal transport properties in skutterudites.

• 出版日期2018-2-15
• 单位吉林大学