PTCR behaviour of highly donor doped BaTiO3

The electrical properties of donor doped BaTiO3 samples with a donor concen tration >0.3 mol% were studied. Samples were sintered at a low partial pres sure of oxygen in order to facilitate the,anomalous grain growth and donor incorporation. In order to optimise the PTCR anomaly the samples were annea led in an oxidising atmosphere. The samples were characterised using impeda nce spectroscopy and SEM. Results show that by the use of a specific sinter ing profile PTCR ceramics containing a higher amount of donor dopant can be prepared. (C) 1999 Elsevier Science Limited. All rights reserved.