Effect of phosphor doping on the microstructure and dielectric properties of barium titanate ceramics

• Published in: Materials chemistry and physics 1998-09, Vol.55 (3), p.193-196
• Main Authors: Wang, Xiao-hui, Gui, Zhi-lun, Long-tu, Li
• Format: Article
• Language: English
• Subjects: Barium titanate BaTiO 3; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric properties; Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Doping of phosphor; Exact sciences and technology; Niobates, titanates, tantalates, pzt ceramics, etc; Physics; Ultrafine powders
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/S0254-0584(98)00120-5

The effect of phosphor doping on the sintering behaviour, microstructure and dielectric properties of BaTiO 3 has been investigated. Diisopropyl phosphinate is added to high-purity BaTiO 3 powder prepared by the wet chemical method with a final amount of 0.14 wt.% P 2O 5 with respect to the BaTiO 3. Phosphor-doped BaTiO 3 ceramics with a high density and uniform grain size have been produced by using wet processing and pressureless sintering without any binder. A scanning electron microscope, thermometric analysis, X-ray diffraction and an impedance analyser have been used to determine the microstructure as well as the dielectric properties. The phosphor cations can form a liquid phase belonging to the ternary system BaO-TiO 2-P 2O 5, leading to the formation of BaTiO 3 ceramics with high density at low temperature. Phosphor-doped BaTiO 3 ceramics with a high density of 96% D th are obtained by sintering at 1200°C with a soaking time of 2 h. The dielectric constants of samples sintered at 1150 and 1200°C are as high as 6100 and 5500, respectively; the Curie temperature of samples decreases with decreasing sintering temperature. Doping with a small amount of phosphor can improve the sintering and dielectric properties of BaTiO 3 ceramics.