| 摘要 |
<p>A piezoelectric element (10) includes a plurality of piezoelectric layers (12,14) composed of a piezoelectric material containing Sr, Bi, Ti, and O, at least three vibration electrodes (16,18,20) opposing each other, each disposed among the piezoelectric layers, and an energy-confining region formed in a region in which the vibration electrodes (16,18,20) overlap, the energy-confining region being parallel to the planes of the vibration electrodes (16,18,20) and exciting an n-th harmonic longitudinal thickness vibration. The maximum length L of a secant between two intersections on the periphery of the energy-confining region and the distance t between the topmost vibration electrode (18) and the bottommost vibration electrode (20) satisfy an nL/t ratio of less than 10. The piezoelectric element (10) is thermally stable and has a narrow allowable error. <IMAGE></p> |
