A TEM study of grain boundaries in internal boundary layer capacitors based on donor-doped (Sr, Ca) TiO3 ceramics

F Poignant (1) , G Trolliard (2) , P Abelard (3)

1 RWTH - Rheinisch-Westfälische Technische Hochschule Aachen University
2 LMCTS - Laboratoire de Matériaux Céramiques et Traitements de Surface
3 ENSCI - Ecole Nationale Supérieure de Céramique Industrielle

Donor-doped (Sr, Ca)TiO3 ceramics, either oxidized or infiltrated by Bi2O3 and Bi2O3-PbO molten mixtures, have been studied using a transmission electron microscope equipped with EDX facilities. Grain boundary morphologies of these different materials are investigated. In oxidized samples, grain surfaces exhibit a chemical contrast, interpreted as the result of a TiO2 segregation that occurs during the sintering stage. Moreover, the in-detail characterization of infiltrated specimens reveals that intergranular regions present a facies strongly influenced by the type of mixture used. During the infiltration step, grains are slightly dissolved by molten oxides and Pb noticeably enhances this process.

Domaines: Matériaux; Matériaux

F Poignant, G Trolliard, P Abelard. A TEM study of grain boundaries in internal boundary layer capacitors based on donor-doped (Sr, Ca) TiO3 ceramics. Journal of Materials Science: Materials in Electronics, 1997, 8 (3), pp.139-146. ⟨10.1023/A:1018533827407⟩. ⟨hal-03625879⟩