| 摘要 |
PROBLEM TO BE SOLVED: To obtain a piezoelectric element which can realize an vibrator of high performance, which is excellent in thermal stability in a piezoelectric element which excites third vertical harmonic vibration in the thickness direction. SOLUTION: A piezoelectric element 10 includes a piezoelectric substrate 12. The piezoelectric substrate 12 is formed of a CaBi4Ti4O15-basis piezoelectric material. Vibration electrodes 14, 16 are formed on both surfaces of the piezoelectric substrate 12. An energy confinement region is formed in a region wherein the vibration electrodes 14, 16 overlap with each other between the electrodes. When a straight line inside an energy confinement region parallel to the vibration electrodes 14, 16 is cut out at two points which intersect an outer circumference of an energy confinement region, its maximum length is L and the total thickness of an element is (t); then the value of L/t is set to be 9 or less. |
