Sintering Behavior, Electrical and Mechanical Properties of Barium Titanate Ceramics Doped with BaB2O4
Nobuyuki TAKEUCHI, Yuji YAMASAKI and Shingo ISHIDA
Abstract:Effects of sintering additives on mechanical and electrical properties of Gd-doped barium titanate ceramics have been studied by measuring their electrical resistivity, bending strength, and ESR spectra. The bulk density of the sample prepared by sintering at 1100 with small amounts of BaB2O4 doped as sintering aids was as high as 90% of the theoretical value. Semiconducting BaTiO3 was obtained by sintering the BaB2O4-doped samples at 1100. The electrical resistivity of the 3mol% BaB2O4-doped sample sintered at 1100 was the lowest in all samples and its PTCR jump was more than 4 orders of magnitude. In addition, the bending strength of the sample was the highest in all samples and the value was close to that of the sample sintered at 1380 without sintering additives. The line width of the ESR signal of Gd3+ observed in the sample sintered at 1100 with BaB2O4 was almost equal to that in the sample sintered at 1380 without sintering additives. The result showed that in the samples doped with BaB2O4 as a sintering aids, Gd3+ ions were dissolved uniformly in BaTiO3 grains at a sintering temperature of 1100. Key Words:Barium titanate, PTCR, ESR, Bending strength, Electrical resistivity