Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7898183 | Journal of the European Ceramic Society | 2018 | 6 Pages |
Abstract
Grain boundaries of CaCu3Ti4O12 (CCTO) materials have been shown to play leading role in colossal permittivity. Core-shell design is an attractive approach to make colossal dielectric capacitors by controlling the grain boundaries. Core-shell grains of CCTO surrounded by Al2O3 shell were synthesized by ultrasonic sol-gel reaction from alumina alkoxide precursor. The influence of alumina shell by comparison with bare CCTO grains was studied. Particularly, microstructure, dielectric and electric effects on sintered ceramics are reported. The average grain size and the density are increased compared to undoped CCTO leading to an improvement of permittivity from 58,000 to 81,000 at 1â¯kHz. Furthermore a decrease of dielectric loss is found in a frequency range of 102-103â¯Hz. Moreover, the activation energy of grain boundaries is increased from 0.55 to 0.73â¯eV and the electrical properties such as breakdown voltage, non-linear coefficient and resistivity are improved with the aim of making industrial capacitors.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Sonia De Almeida-Didry, Meledje Martin Nomel, Cécile Autret, Christophe Honstettre, Anthony Lucas, François Pacreau, François Gervais,