| 摘要 |
A piezoelectric device constituted by a piezoelectric body and electrodes. The piezoelectric body is a monocrystalline piezoelectric film formed, above a substrate, of an inorganic crystalline compound containing a first ferroelectric crystal when no electric field is applied to the piezoelectric film, and having a characteristic that phase transition of at least a portion of the first ferroelectric crystal to a second ferroelectric crystal occurs when the electric field strength applied to the piezoelectric film is at or above a predetermined level E1, the first and second ferroelectric crystals correspond to different crystal systems, and the piezoelectric device is driven under a condition that the minimum strength Emin, the maximum strength Emax, and the predetermined level E1 of the applied electric field satisfy the inequalities, Emin<E1<Emax. |
