The Characteristics Development of excess Bi2O3-doped 0.65BiO.5KO.5TiO3+0.35BaTiO3 Ceramics

Recently, there have been widespread discussed about NBT-KBT-BT system, but up to now, relatively few KBT-BT system reports are less found. In this research, piezoelectric materials 0.65 [Bi_0.5K_0.5TiO₃]+0.35[BaTiO₃] with excess x wt% Bi₂O₃ (x=0, 1, 2) are investigated as a function of sintering temperatures. The sintering process is carried out in air for 2 h from 1050degC to 1100degC. The sintering characteristics and dielectric characteristics of 0.65 [Bi_0.5K_0.5TiO₃]+ 0.35 [BaTiO₃]+x wt% Bi₂O₃ ceramics are developed with the aid of SEM, X-ray diffraction, patterns, and dielectric-temperature curves. Dielectric- temperature properties are investigated in the temperature of 30degC~500degC at 10 kHz. From the results of this research, the optimum compositional and sintering condition is X=2 wt% / S_T=1100degC, the maximum dielectric constant epsiv_r is 5818, which is better than the result of sol-gel method (epsiv_r=1652 at 10 kHz) [1].