Journal of Materials Science: Materials in Electronics

, Volume 4, Issue 1, pp 67–73

Field-dependent changeover from current-to voltage-limiting characteristics by non-linear n-type BaTiO3 ceramics


  • V. Ravi
    • Materials Research Centre, Indian Institute of Science
  • T. R. N. Kutty
    • Materials Research Centre, Indian Institute of Science

DOI: 10.1007/BF00226637

Cite this article as:
Ravi, V. & Kutty, T.R.N. J Mater Sci: Mater Electron (1993) 4: 67. doi:10.1007/BF00226637


Non-linear resistors having current-limiting capabilities at lower field strengths, and voltage-limiting characteristics (varistors) at higher field strengths, were prepared from sintered polycrystalline ceramics of (Ba0.6Sr0.4)(Ti0.97Zr0.03)O3+0.3 at % La, and reannealed after painting with low-melting mixtures of Bi2O3 + PbO +B2O3. These types of non-linear characteristics were found to depend upon the non-uniform diffusion of lead and the consequent distribution of Curie points (Tc) in these perovskites, resulting in diffuse phase transitions. Tunnelling of electrons across the asymmetric barrier at tetragonak-cubic interfaces changes to tunnelling across the symmetric barrier as the cubic phase is fully stabilized through Joule heating at high field strengths. Therefore the current-limiting characteristics switch over to voltage-limiting behaviour because tunnelling to acceptor-type mid-bandgap states gives way to band-to-band tunnelling.

Copyright information

© Chapman & Hall 1993