Influence of Oxygen Substoichiometry on the Dielectric Properties of BaTiO3‐δ Nanoceramics Obtained by Spark Plasma Sintering. (8th April 2013)

• Record Type: Journal Article
• Authors: Voisin, Christophe; Guillemet‐Fritsch, Sophie; Dufour, Pascal; Tenailleau, Christophe; Han, Hyuksu; Nino, Juan C.
• Is Part Of: International journal of applied ceramic technology. Volume 10(2013)Supplement 1
• Page Start: E122
• Page End: E133
• Publication Date: 2013-04-08
• Subjects: Ceramics -- Periodicals; Ceramics -- Technological innovations -- Periodicals; 620.1405
• DOI: 10.1111/ijac.12058
• Languages: English
• ISSNs: 1546-542X

Abstract

Abstract : Oxygen‐deficient BaTiO3‐δ nanoceramics were prepared by spark plasma sintering. Partially reduced raw nanopowders led to unusual dielectric properties. A short postsintering treatment was performed to reach a high εr /tan δ, which makes them attractive for industrial applications such as low‐frequency capacitors. Surprisingly, our ceramics also remained black even after annealing for 5 days at 850°C in air, indicating the presence of barriers against oxygen diffusion. This exceptional behavior in pure barium titanate was consistent with a core–shell structure made of semiconductive grains and insulating grain boundaries, due to the presence of Ti 3+ /Ti 4+ and oxygen vacancies.