摘要
采用熔融法结合放电等离子烧结(SPS)技术合成了P型填充方钴矿化合物Sr_(0.5)Co_(4-x)Fe_xSb_(12),并研究了Fe掺杂对该化合物高温热电性能的影响。采用X-射线衍射(XRD)及电子探针(EPMA)表征了化合物的物相及化学成分,在300～850 K温度范围内测试了化合物的电导率、赛贝克系数和热导率,采用Van de Pauw方法测试了化合物的室温载流子浓度。实验结果表明,化合物的主要相组成为Sr_(0.5)Co_(4-x)Fe_xSb_(12)方钴矿相,同时含有少量FeSb_2和CoSb_2杂质相。化合物的赛贝克系数均为正值,表明为空穴导电。随着Fe掺杂量的增加,化合物的载流子浓度及电导率增加,赛贝克系数降低,晶格热导率降低,最小室温晶格热导率为1.97 Wm^(-1)K^(-2)。对于化合物Sr_(0.52)Co_(2.32)Fe_(1.68)Sb_(12),在850K时获得的最大热电性能指数ZT约为0.60。
Skutterudite compounds Sr0.5Co4-xFexSb12 were synthesized by melting method and the thermal and electrical properties were measured in the temperature range of 300-850 K. The results of X-ray diffraction （XRD） and electron microprobe analyses （EPMA） identified that all the samples contain Sr0.5Co4-xFexSb12 skutterudite as the main phase with a trace amount of FeSb2 and CoSb2 impurities. All samples exhibit p-type conduction. The carrier concentration and electrical conductivity of the samples increase with increasing iron content and the Seebeck coefficient decreases. The lattice thermal conductivity of the samples decreased with the increase of iron content due to the vacancy point defect phonon scattering at Co site introduced by iron. The lowest lattice thermal conductivity at room temperature is about 1.97 WmtK2. The highest ZT value of 0.6 is obtained for Sr0.52Co2.32Fe1.68Sbt2 compound at 850 K.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2007年第A02期415-418,共4页
Rare Metal Materials and Engineering
基金
国际重大合作项目基金(No.50310353)
杰出青年基金(No.50325208)资助
