Abstract
Semiconducting BaTiO3-based ceramics originating from the same starting powder batch were subjected to different oxidative post-sintering treatments at temperatures between 800 °C and 1200 °C. The annealing profiles were chosen in a way to result in ceramics with same room-temperature and microstructure. However, the different annealing procedures clearly affected the resulting PTCR characteristics above and below the phase transition temperature. Observed changes in electrical properties were investigated by capacitance-voltage measurements and x-ray diffraction. It was found that annealing treatments influence the grain boundary potential barrier height and width by modifying the equilibrium concentration of cation and oxygen vacancies. Moreover, oxidative annealing at 1100 °C appears to influence the temperature development of spontaneous polarization by filling up oxygen vacancies within the grain bulk. These findings not only extent existing knowledge about defect equilibria in barium titanate but also emphasize the strong impact of process parameters on electrical properties of electroceramics.
Original language | English |
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Pages (from-to) | 179-187 |
Number of pages | 9 |
Journal | Journal of the European Ceramic Society |
Volume | 41 |
Issue number | 16 |
DOIs | |
Publication status | Published - Dec 2021 |
Keywords
- Defects
- Grain boundary
- Potential barrier
- Temperature treatment
- Varistor effect
ASJC Scopus subject areas
- Ceramics and Composites
- Materials Chemistry