| abstract |
The present invention is directed to a new group of pure and doped bismuth layer structured perovskite high temperature piezoelectric ceramics and sensors made of the same. The new materials have the formula of [Bi 2 O 2 ][A m-1 B m O 3m+1 ], where m=2, A is mono-, di-, or trivalent ions or a combination of them, B is transition elements such as Fe 3+ , Ti 4+ , Nb 5+ , Ta 5+ , W 6+ , Mo 6+ or a combination of them. The ceramics have high Curie temperature of 900~940 °C. The sensors claimed in the present invention utilize [Bi 2 O 2 ][A m_1 B m O 3m+1 ] ceramics parts as sensing elements in various shapes and dimensions and can be used to sense force, acceleration, and pressure at very high temperatures. |