Influence of Bi3+ ions in enhancing the magnitude of positive temperature coefficients of resistance in n-BaTiO3 ceramics

  • P. Padmini
  • T. R. N. Kutty
Papers

Abstract

Bi3+ ions substituting at Ba-sites in a limited concentration range with another donor dopant occupying the Ti-sites in polycrystalline BaTiO3 enhanced the positive temperature coefficient of resistance (PTCR) by over seven orders of magnitude. These ceramics did not require normal post sinter annealing or a change to an oxygen atmosphere during annealing. These ceramics had low porosities coupled with better stabilities to large applied electric fields and chemically reducing atmospheres. Bi3+ ions limited the grain growth to less than 8 Μm in size, they enhanced the concentration of acceptor-type trap centres at the grain-boundary-layer regions and maintained complete tetragonality at low grain sizes in BaTiO3 ceramics.

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Copyright information

© Chapman & Hall 1994

Authors and Affiliations

  • P. Padmini
    • 1
  • T. R. N. Kutty
    • 1
  1. 1.Materials Research Centre, Indian Institute of ScienceBangaloreIndia

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