Synthesis and high temperature thermoelectric transport properties of Si-based type-Ⅰ clathrates  

作　　者：邓书康 唐新峰 唐润生 

机构地区：[1]Education Ministry Key Laboratory of Renewable Energy Advanced Materials and Manufacturing Technology [2]Yunnan Normal University [3]State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology

出　　处：《Chinese Physics B》2009年第7期3084-3089,共6页中国物理B（英文版）

基　　金：Project supported by the National Basic Research Program of China (Grant Nos 2007CB607501 and 2007CB607503);Yunnan Natural Science Fund (Grant No 2008CD114)

摘　　要：N-type Si-based type-Ⅰ clathrates with different Ga content were synthesized by combining the solid-state reaction method,melting method and spark plasma sintering （SPS） method.The effects of Ga composition on high temperature thermoelectric transport properties were investigated.The results show that at room temperature,the carrier concentration decreases, while the carrier mobility increases slightly with increasing Ga content.The Seebeck coefficient increases with increasing Ga content. Among all the samples,Ba7.93Ga17.13Si28.72exhibits higher Seebeck coefficient than the others and reaches -135μV·K^-1 at 1000 K.The sample prepared by this method exhibits very high electrical conductivity,and reaches 1.95x 10^5 S·m^-1 for Ba8.01Ga16.61Si28.93 at room temperature.The thermal conductivity of all samples is almost temperature independent in the temperature range of 300-1000 K,indicating the behaviour of a typical metal.The maximum ZT value of 0.75 is obtained at 1000 K for the compound Ba7.93Ga17.13Si28.72.N-type Si-based type-Ⅰ clathrates with different Ga content were synthesized by combining the solid-state reaction method,melting method and spark plasma sintering （SPS） method.The effects of Ga composition on high temperature thermoelectric transport properties were investigated.The results show that at room temperature,the carrier concentration decreases, while the carrier mobility increases slightly with increasing Ga content.The Seebeck coefficient increases with increasing Ga content. Among all the samples,Ba7.93Ga17.13Si28.72exhibits higher Seebeck coefficient than the others and reaches -135μV·K^-1 at 1000 K.The sample prepared by this method exhibits very high electrical conductivity,and reaches 1.95x 10^5 S·m^-1 for Ba8.01Ga16.61Si28.93 at room temperature.The thermal conductivity of all samples is almost temperature independent in the temperature range of 300-1000 K,indicating the behaviour of a typical metal.The maximum ZT value of 0.75 is obtained at 1000 K for the compound Ba7.93Ga17.13Si28.72.

关 键 词：type-Ⅰ clathrate thermoelectric materials SYNTHESIS 

分 类 号：TB34[一般工业技术—材料科学与工程]