Preparation and thermoelectric transport properties of Ba-, La- and Ag- doped Ca3Co4O9 oxide materials  

作　　者：ZHANG Feipeng LU Qingmei LITingxian ZHANG Xin ZHANG Jiuxing SONG Xiaoyan 

机构地区：[1]Department of Applied Sciences, Henan University of Urban Construction, Pingdingshan 467036, China [2]Key Laboratory of Advanced Functional Materi- als, Chinese Ministry of Education, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China [3]College of Phys- ics and Electrical Engineering, Anyang Normal University, Anyang 455002, China

出　　处：《Journal of Rare Earths》2013年第8期778-783,共6页稀土学报（英文版）

基　　金：Foundation item： Project supported by National Natural Science Foundation of China （50801002）, Beijing Municipal Natural Science Foundation （2112007） and the Education Department of Henan Province Science and Technology Research Projects （13B430895）

摘　　要：The Ba-, La- and Ag-doped polycrystalline Ca2.9M0.1Co4O9 （M=Ca, Ba, La, Ag） thermoelectric bulk samples were pre- pared via citrate acid sol-gel synthesis method followed by spark plasma sintering technique. The bulk samples were characterized and analyzed with regard to their phase compositions, grain orientations as well as microstructures. The high temperature thermoelec- tric transport properties of the bulk samples were studied in detail. All bulk samples were found to be single-phased with modified body texture. The electrical resistivity was modulated as a result of carrier concentration modification, however the carrier transport process was not influenced; the Seebeck coefficient was deteriorated simultaneously. The total thermal conductivity was remarkably reduced, on account of the decreasing of phonon thermal conductivity. The thermoelectric properties of the Ba-, La-, and Ag-doped bulk samples were optimized, and the Ba-doped Ca2.9Ba0.1Co4O9 system was found to have the highest dimensionless figure of merit ZT0.20 at 973 K, which was remarkably higher than that of the un-doped sample.The Ba-, La- and Ag-doped polycrystalline Ca2.9M0.1Co4O9 （M=Ca, Ba, La, Ag） thermoelectric bulk samples were pre- pared via citrate acid sol-gel synthesis method followed by spark plasma sintering technique. The bulk samples were characterized and analyzed with regard to their phase compositions, grain orientations as well as microstructures. The high temperature thermoelec- tric transport properties of the bulk samples were studied in detail. All bulk samples were found to be single-phased with modified body texture. The electrical resistivity was modulated as a result of carrier concentration modification, however the carrier transport process was not influenced; the Seebeck coefficient was deteriorated simultaneously. The total thermal conductivity was remarkably reduced, on account of the decreasing of phonon thermal conductivity. The thermoelectric properties of the Ba-, La-, and Ag-doped bulk samples were optimized, and the Ba-doped Ca2.9Ba0.1Co4O9 system was found to have the highest dimensionless figure of merit ZT0.20 at 973 K, which was remarkably higher than that of the un-doped sample.

关 键 词：Ca3Co4O9 oxide Ca-site doping thermoelectric transport properties rare earths 

分 类 号：TQ175.71[化学工程—硅酸盐工业] TN213