| Piezoelectric ceramics have been widely used in electrical devices such as sensors,drivers,ultrasonic generators and filters. It's a functional materials which can transform electricity into mechanism.Pb(Zr,Ti)O3-based piezoelectric ceramics (PZT) is a typical applied piezoelectric materials because of their excellent piezoelectric properties, Owing to the environmental pollution caused by PbO contained in lead-based piezoelectric devices, with high attention on environment protection, recent researches on the fabrication of high performance lead-free piezoelectric ceramics have attracted much attention in world wide range. Many researchers have attempted to improve the piezoelectric properties of lead-free ferroelectrics.Barium titanate is studied in this article, because it's poor piezoelectric properties and low curie temperature, we discuss them respectively. First we establish matrix——particle model to discuss the relationship between stress and curie temperature. then verify it by experiment. That is establish barium titanate——cordierite model. The experiment results indicate that with the increase of stress, the curie temperature increase correspondingly. When 14 percent cordierite by volume add into barium titanate, the optimal result of curie temperature in this system was 140.1℃.For several decades, BaTiO3 ceramics had been known to have only a d33 level of 190 pC/N, but in recent years, surprisingly high d33 values(460 pC/N) were reported for those BaTiO3 ceramics that were prepared by improve technology (such as two-step sintering ). Therefore, this article study the BaTiO3 ceramics systematically. First, we establish physical model of BaTiO3 microstructure. Then the contribution of piezoelectric properties in different phase is discussed, As to the experiment, we study the effect of sintering temperature on piezoelectric properties in BaTiO3, the result exhibits when the sintering temperature is 1260℃, the piezoelectric coefficient( d33)can up to 370pC/N。... |
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