Materials of Bi4Ti3O12 type for high temperature acoustic piezo-sensors

Ceramics of bismuth titanate family Bi4Ti3O12 were prepared by the classic sintering process. A composition with a W6+ ion substitution and an additio n of a small amount of Cr2O3 was perfected. Piezoelectric properties of thi s material studied as a function of temperature showed a good stability up to 500 degrees C. A sensor device was manufactured like a buzzer. Its respo nse to an acoustic signal was studied up to 300 degrees C. The electric and piezoelectric study of the material deposited as a thick film shows the po ssibility to obtain a sensor prepared with this technology working at highe r temperatures. (C) 1999 Elsevier Science S.A. All rights reserved.