J Mater Sci Technol ›› 2009, Vol. 25 ›› Issue (04): 535-538.

• Articles • Previous Articles     Next Articles

High-temperature Electric Properties of Polycrystalline La-doped CaMnO3 Ceramics

Jinle Lan1), Yuanhua Lin1)†, Ao Mei1), Cewen Nan 1)†, Yong Liu2), Boping Zhang2), Jingfeng Li1)   

  1. 1) State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
    2) School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
  • Received:2008-06-30 Revised:2009-01-20 Online:2009-07-28 Published:2009-10-10
  • Contact: Yuanhua Lin, Cewen Nan
  • Supported by:

    the National Program on Key Basic Research Project ("973 Program") under grant No. 2007CB607505
    the National High Technology Research and Development Program of China under grant No. 2009AAO3Z216.

Abstract:

Polycrystalline La-doped CaMnO3 ceramics have been prepared by a solid-state sintering method. Analysis of microstructure and phase composition indicates that the addition of La can prohibit the further growth of grain, and no impurity phase appears. The results revealed that the La doping can lead to a large change of the activation energy (from 0.22 to 0.02 eV), and thus result in a marked increase in electric conductivity of 2-4 orders of magnitude. The power factor can reach about 1.5×10-4 W?m-1?K-2 in a wide temperature range, which potentially make them attractive for n-type high-temperature thermoelectric materials.

Key words: CaMnO3, Thermoelectric, Activation energy, Seebeck coefficient