Ag_xPb_mSbSe_(m+2)纳米一微米复合热电材料的制备及其性能  

Fabrication of Ag_xPb_mSbSe_(m+2) Thermoelectric Nanomaterial by Pressureless Sintering

作　　者：贺香荣[1] 张爱霞[1] 蔡克峰[1] 

机构地区：[1]同济大学功能材料研究所,上海200092

出　　处：《稀有金属材料与工程》2007年第A02期392-394,共3页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50371062);上海市科学技术委员会(05ZR14124);浦江人才计划的资助

摘　　要：以硝酸铅、硝酸银、硝酸锑、硒粉为原料,硼氢化钾为还原剂,水热合成出Ag_xPb_mSbSe_(m+2)(m=10,14,18,x=1,0.85)纳米粉末。X-射线衍射分析表明粉末均呈NaCl型晶体结构,粒径在20～60nm之间。采用无压烧结的方法制备了热电块体材料。扫描电子显微镜观察表明烧结体由纳米和微米两种晶粒组成,前者被包裹在后者内,试样的相对密度大于90%,最高的达96.3%。详细研究了不同成分的试样在同一烧结条件下的体积收缩、烧失量和气孔率,测试了Ag_(0.85)Pb_(18)SbSe_(20)从室温至450℃的热电性能。其Seebeck系数随温度提高单调增加,450℃时达到275μY/K;电导率随温度提高先增加后降低,165℃时达到最大值:196Ω^(-1)cm^(-1)。Silver and antimony co-doped PbSe （AgxPbmSbSem＋2） （m=10, 14, 18, x=1, 0.85） nanopowders were hydrothermal synthesized, using lead nitrate, silver nitrate, antimony nitrate and selenium powder as starting materials, and KBH4 as a reductant. X-Ray diffraction analyses show that the powders have the same crystal structure as NaCl and that the grain size of the nanopowders varies from 20 to 60 nm Thermoelectric bulk materials were fabricated by pressureless sintering. SEM observations reveal that the grain size of the sintered samples is in two scales： one is in nanoscale -100 nm） and the other is in micron scale （-2 μm） and that the micron-scale grains contain the nanograins. The relative densities of the sintered samples are 〉90% and the highest one reaches 96.3%. The volume change, mass loss and porosity of the samples with the composition were studied in detail under the same sintering conditions. The thermoelectric properties of the samples were measured from room temperature to 450 ℃. Seebeck coefficient of the sintered Ag0.85Pb18SbSe20 sample monotonically increases with temperature and reaches -275μV/K at 450 ℃, while the electrical conductivity firstly increases with temperature and then decreases with temperature and reaches a highest value of 196 Ω^-1cm^-1, at 165 ℃.

关 键 词：水热合成 热电材料 无压烧结 热电性能 

分 类 号：TB34[一般工业技术—材料科学与工程]