非化学计量比AgSbTe_(2+x)化合物制备及热电性能  

Synthesis and thermoelectric properties of nonstoichiometric AgSbTe_(2+x) compounds

作　　者：杜保立[1,2] 徐静静[1] 鄢永高[1] 唐新峰[1] 

机构地区：[1]武汉理工大学材料复合新技术国家重点实验室,武汉430070 [2]河南理工大学物理化学学院,焦作454000

出　　处：《物理学报》2011年第1期765-771,共7页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(批准号:2007CB607501)资助的课题~~

摘　　要：采用高纯元素直接熔融、淬火并结合放电等离子烧结方法制备了非化学计量比AgSbTe2+x(x=0—0.05)系列样品,研究了不同Te含量在300—600K范围内对样品热电性能的影响规律.结果表明:随着Te含量的增加,Ag+离子空位浓度增加,空穴浓度和电导率大幅度提高,Seebeck系数减小.热导率随Te过量程度的增加略有增加,但所有Te过量样品的晶格热导率均介于0.32—0.49W/mK之间,低于化学计量比样品的值,接近理论最低晶格热导率.AgSbTe2.01(x=0.01)样品具有最佳的综合热电性能,其热电优值ZT在562K达到1.41,与AgSbTe2化合物相比增加了15%.Nonstoichiometric AgSbTe2 ＋x（x = 0—0. 05） compounds have been prepared by combining melting-quench and spark plasma sintering. The effects of excessive Te on thermoelectric properties were investigated at 300 K to 600 K. Results indicated that the concentration of Ag ＋ ion vacancy,hole concentration and electrical conductivity increase remarkably with the increasing amount of Te,while the Seebeck coefficient decreases. In addition,the total thermal conductivity of the samples increases slightly as Te content increases. The lattice thermal conductivities of nonstoichiometric samples range from 0. 32 to 0. 49 W/mK,which are less than the value of the stoichiometric sample,and close to the theoretical minimum thermal conductivity. For AgSbTe2.01（x = 0. 01）,a maximum figure of merit ZT = 1. 41 was obtained at 562K. This value is 15% higher than that of the stoichiometric sample.

关 键 词：AgSbTe2 非化学计量比 热电性能 热导率 

分 类 号：O482.6[理学—固体物理]