摘要
We fabricate Sm-doped Ca3Co4O9+δ(CCO)bulk materials in magnetic field during both processes of chemical synthesis and cold pressing.The structure and electrical performance of the samples are investigated.With the increasing Sm concentration,the electrical conductivity 1/ρ decreases and the Seebeck coefficientαincreases.As a result,the power factor(PF=α^2/ρ)is raised slightly.After applying magnetic field,the extent of texture,grain size and density of all the bulk materials are improved obviously,thereby an enhanced electrical conductivity can be gained.Additionally,the degeneracy of Co^4+ state in the CoO2 layer of CCO is also increased as the magnetic field is used in the preparing process,which results in an enhancedα.The Ca2.85Sm0.15Co4O9+δ prepared in magnetic field shows the largest power factor(0.20 mW·m^-1·K^-2 at 1073 K).
作者
Xiu-Rong Qu
Yan-Yan Xu
Shu-Chen Lü
Jian-Min Hu
曲秀荣;徐岩岩;吕树臣;胡建民(Key Laboratory of Photonic and Electric Bandgap Materials,and School of Physics and Electronic Engineering,Harbin Normal University,Harbin 150025,China;School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China)
基金
Project supported by the National Natural Science Foundation of China(Grant No.51302055)。
