Investigate the characteristics of Bi₂O₃-added 0.35 (K₀.₅Bi_0.5TiO₃)-0.65 BaTiO ₃ ceramics

In this study, 0.35 K_0.5Bi_0.5TiO₃-0.65 BaTiO₃ composition (abbreviated as 0.35 KBT-0.65 BT3) was synthesized using a two-step calcination process, that combined hydrothermal (heated at 200°C for 2 h) and conventionally calcining (calcined at 850°C for 2 h) processes. After calcination, 0∼3wt% Bi₂O₃ was added into the 0.35 KBT-0.65 BT3 composition (0.35 KBT-0.65 BT3-X, X=0, 1, 2, and 3) as the sintering aid and for compensating the vaporization of Bi ₂O₃during the sintering process. After mixing with Bi ₂O₃, 0.35 KBT-0.65 BT3-X ceramics were sintered at 1050°C∼1125°C in air for 2h, and the sintering and dielectric characteristics of the 0.35 KBT-0.65 BT3-X ceramics were well developed. The X-ray diffraction (XRD) pattern and scanning electronic microscope (SEM) observation were used to analyze the variations of crystalline phase and microstructure of the 0.35 KBT-0.65 BT3-X ceramics. Temperature-dependent dielectric characteristics were measured with oscillating amplitude (50 mV) at 100 KHz by an HP4294A impedance analyzer by putting the sintered ceramics in a temperature-programmable testing chamber. The range of measured temperature was changed from 25°C to 500°C in order to find the maximum dielectric constant and Curie temperature of the 0.35 KBT-0.65 BT3-X ceramics.