Papers by Author: Wei Zhao

Abstract: A lead-free piezoelectric ceramic binary system based on bismuth sodium titanate (Bi0.5Na0.5)TiO3 (BNT)-bismuth potassium titanate (Bi0.5K0.5)TiO3 (BKT) was synthesized by conventional mixed-oxide technique. The XRD analysis showed that the rhombohedral-tetragonal morphotropic phase boundary (MPB) of the Bi0.5 (Na1-xKx)0.5 TiO3 system was in the composition range of x = 0.16 ~ 0.20. In addition, the piezoelectric properties of this system were also investigated. It was indicated that the piezoelectric properties are better with the compositions near the rhombohedral phase within the MPB than the compositions near the tetragonal phase.

Abstract: A citrate method to synthesize 0.94Bi0.5Na0.5TiO3-0.06BaTiO3 nano-powder was studied. The stable gel was obtained by the control of the pH value and temperature of the precursor solution. The BNBT nano-powder was produced after calcining the xerogel at 600°C~800°C. The average grain size of the powder calcined at 700°C for 3 h is 50 nm, and the grain size of the ceramic sintered at 1080°C is 0.7 μm. The sintering temperature used is 100°C lower than the BNBT ceramic prepared by traditional method, but the electrical properties were comparable. In addition, it was found that the ball-milling process has important effect on the morphology of the ceramics and the orientation crystals were eliminated due to the disintegration of agglomerates during milling.