Dielectric properties of CaCu3Ti4O12 based multiphased ceramics

Sophie Guillemet (1) , Thierry Lebey (2) , Madona Boulos (1) , Bernard Durand (1)

1 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux
2 LGET - Laboratoire de génie électrique de Toulouse

A “soft chemistry” method, the coprecipitation, has been used to synthesize the perovskite CaCu3Ti4O12 (CCT). Three main types of materials were obtained for both powders and sintered ceramics: a monophased consisting of the pure CCT phase, a biphased (CCT + CaTiO3), and a three-phased (CCT + CaTiO3 + copper oxide (CuO or Cu2O)). These ceramics, sintered at low temperature, 1050 °C, present original dielectric properties. The relative permittivity determined in the temperature range (−150 < T < 250 °C) is significantly higher than the one reported in the literature. Internal barrier layer capacitor is the probable mechanism to explain the particular behaviour. Moreover, the presence of a copper oxide phase beside the perovksite CCT plays an important role for enhancing the dielectric properties.

Mots clés: Powders-chemical preparation; Sintering; Dielectric properties; CaCu3Ti4O12; Capacitors

Domaines: Matériaux; Energie électrique

Sophie Guillemet, Thierry Lebey, Madona Boulos, Bernard Durand. Dielectric properties of CaCu3Ti4O12 based multiphased ceramics. Journal of the European Ceramic Society, 2006, 26 (7), pp.1245-1257. ⟨10.1016/j.jeurceramsoc.2005.01.055⟩. ⟨hal-03599312⟩