Synthesis and High Temperature Thermoelectric Properties of Ca_(2.7-x)Er_(0.3)Na_xCo_4O_(9+δ)

作     者：裴健 陈刚 陆冬青 滕玉洁 

作者机构：Department of Applied Chemistry Harbin Institute of Technology 

出 版 物：《Journal of Rare Earths》 (稀土学报（英文版）)

年 卷 期：2007年第25卷第S1期

页      面：395-399页

核心收录：

学科分类：0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 070205[理学-凝聚态物理] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0702[理学-物理学] 

基　　金：the National Nature Science Foundation of China (20571019) Project-sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars ,Heilongjiang (LC06C13) Program of Harbin Subject Chief Scientist 

主　　题：Co-based oxides sol-gel process electrical properties rare earths 

摘      要：Polycrystalline Ca2.7-xEr0.3NaxCo4O9+δ (x=0, 0.05, 0.1, 0.15) samples were prepared using a sol-gel process followed by hot-pressing technique sintering and their high-temperature thermoelectric properties were measured from 350 up to 1073 K. The results showed that with the increase of the dopant amount of Na, the electrical conductivity increased, while the Seebeck coefficient and thermal conductivity decreased. The electrical conductivity was dominated by polaron hopping conductivity mechanism above about 550 K and the Na+ substitution for Ca2+ could not change the transport mechanism. The dimensionless figure of merit ZT value reaches 0.31 for Ca2.55Er0.3Na0.15Co4O9+δ at 1073 K, which suggested that Ca2.7-xEr0.3NaxCo4O9+δ (x=0, 0.05, 0.1, 0.15) were good potential oxides for thermoelectric application.