Effect of nanocomposite structure on the thermoelectric properties of 0.7-at% Bi-doped Mg_2 Si nanocomposite  

作　　者：杨梅君 沈强 张联盟 

机构地区：[1]Centre for Materials Research and Analysis, Wuhan University of Technology [2]State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology

出　　处：《Chinese Physics B》2011年第10期355-361,共7页中国物理B（英文版）

基　　金：supported by the National Basic Research Program of China (Grant No. 2007CB607501);the Fundamental Research Funds for the Central Universities

摘　　要：Nanocomposites offer a promising approach to the incorporation of nanostructured constituents into bulk thermo- electric materials. The 0.7-at% Bi-doped Mg2Si nanocomposites are prepared by spark plasma sintering of the mixture of nanoscale and microsized 0.7-at% Bi-doped Mg2Si powders. Microstructure analysis shows that the bulk material is composed of nano- and micrograins. Although the nanograin hinders electrical conduction, the nanocomposite struc- ture is more helpful to reduce thermal conductivity and increase the Seebeck coefficient, hence improving thermoelectric performance. A dimensionless figure of merit of 0.8 is obtained for the 0.7-at% Bi-doped Mg2Si nanocomposite with 50-wt % nanopowder, which is about twice larger than that of the sample without nanopowder.Nanocomposites offer a promising approach to the incorporation of nanostructured constituents into bulk thermo- electric materials. The 0.7-at% Bi-doped Mg2Si nanocomposites are prepared by spark plasma sintering of the mixture of nanoscale and microsized 0.7-at% Bi-doped Mg2Si powders. Microstructure analysis shows that the bulk material is composed of nano- and micrograins. Although the nanograin hinders electrical conduction, the nanocomposite struc- ture is more helpful to reduce thermal conductivity and increase the Seebeck coefficient, hence improving thermoelectric performance. A dimensionless figure of merit of 0.8 is obtained for the 0.7-at% Bi-doped Mg2Si nanocomposite with 50-wt % nanopowder, which is about twice larger than that of the sample without nanopowder.

关 键 词：intermetallic compounds NANOSTRUCTURES SEMICONDUCTORS thermoelectric effects 

分 类 号：TB383.1[一般工业技术—材料科学与工程]