| 摘要 |
The invention provides a novel type of piezoelectric element. This element comprises a number of piezoelectric layers of a ceramic material and a number of electrode layers of a silver-palladium alloy. The piezoelectric layers and the electrode layers are stacked alternately to form a multilayer. This multilayer is also provided with at least two external electrical connections which are in contact with a number of said electrode layers. In accordance with the invention, the composition of the main component of the ceramic material corresponds to the formula:[Pb1-u-xAguREx][Ti1-y-zZry(W+E,fra 1/2+EE Mg+E,fra 1/2+EE )z]O3,where RE is at least one element selected from the group formed by La, Nd, Sm and Gd, and in which 0<u</=0.025; 0.005</=x</=0.05; 0.44</=y</=0.52 and 0.015</=z</=0.1. Preferably, RE stands for La and 0.005<u<0.020. This material can be sintered at a low temperature and has a relatively high Curie temperature. It has further been found that the temperature-dependence of the piezoelectric properties is relatively small in the range around 150 DEG C. The invention also provides a method of manufacturing said piezoelectric elements as well as a novel ceramic composition having piezoelectric properties. |
