Development of bimorph vibrator using lead free BNT piezoelectric film deposited by hydrothermal method
PZT piezoelectric film synthesized hydrothermally has been studied actively in our laboratory. However, it is apprehended recently that PZT affects health and the environment, because PZT is chemical compound containing lead. Therefore, we tried to synthesize lead free BNT piezoelectric film on titanium substrate hydrothermally. The synthesized BNT films on titanium substrates were evaluated with SEM image, XRD pattern and EDS. We fabricated bimorph vibrators with synthesized lead free BNT film and evaluated their performances.
Effect of sintering temperature on microstructure of hydrothermally prepared bismuth sodium titanate ceramics
Abstract Bismuth sodium titanate (Bi 1/2 Na 1/2 TiO 3 or BNT) powders were prepared by the hydrothermal route with starting chemicals containing Bi(NO 3 ) 3 .5H 2 O, NaNO 3 and Ti[i-OPr] 4 in a PTFE-lined autoclave. After hydrothermal treatment at 200 °C for 20 h, the powders were filtered and washed with deionized water until the pH of the washing solution was 10. After drying in an oven at 100 °C for 5 h, white powders of BNT were obtained. X-ray diffraction (XRD) patterns of BNT fine powders show that well developed crystallite with a pure perovskite phase have been formed. The powders were pressed into disc shape of 10 mm in diameter and 1.6 mm thick. The green bodies were sintered in close alumina crucible at 800, 900, 1000 and 1050 °C for 3 h, to obtain the highest density. The microstructure of the powders and ceramics were investigated by scanning electron microscopic (SEM) technique.
Hydrothermal synthesis of advanced ceramic powders
Fabrication par traitement hydrothermal des poudres de ceramiques electroniques et thermomecaniques