SOLID STATE SINTERING PREPARED 0.935(Bi0.5Na0.5)TiO3-0.065BaTiO(3) LEAD-FREE CERAMICS: EFFECT OF SINTERING TEMPERATURE

作者：Lidjici Hamza^*; Rguiti Mohamed; Hobar Farida; Courtois Christian; Leriche Anne

来源：Ceramics-Silikaty, 2010, 54(3): 253-257.

• Lead-free ceramics
• sintering temperature
• dielectric and piezoelectric properties

The effects of sintering temperature on structure, microstructure, dielectric and piezoelectric properties of 0.935(Bi-0.5 Na-0.3)TiO3-0.065BaTiO(3)(BNT6.5BT) lead free ceramics prepared by solid sintering technique at 1150-1200 degrees C were investigated. The X-ray diffraction patterns showed that all of the BANT6.5BT ceramics exhibited a single perovskite structure with the co-existence of the rhombohedral and tetragonal phase. A fine and homogeneous grains were observed for samples sintered at 1150 and 1160 degrees C and the increase of the sintering temperature up to 1180-1200 degrees C induces significant grain growth with the appearance of coarse grains. The dielectric constant-tempemture curves of the compositions exhibited strong dispersion with the increasing temperature, and the dielectric loss increased dramatically while the temperature over 230 degrees C. The lowest value of depolarization temperature (T-d) was found at samples sintered at 1160 degrees C. The values of remnant polarization P-r obtained at room temperature are 31 and 29 mu C/cm(2) for specimens sintered at 1160 degrees C and 1200 degrees C respectively At room temperature, BNT6.5BT ceramics sintered at 1180 degrees C exhibited good performances: dielectric constant was 833 at 1 KHz, thick coupling factor k(t) was 0.52 and the k/k(p) ratio was 2.08. Therefore, the ceramics can be suitable for ultrasonic transducers in commercial applications.

• 出版日期2010