| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To stably produce a great magnitude of strain, and to cope with thickness reduction as well in a piezoelectric element. <P>SOLUTION: The piezoelectric element 1 is provided with a piezoelectric body 13 and electrodes 12 and 14 for applying an electric field to the piezoelectric body 13 in a prescribed direction. The piezoelectric body 13 is a single crystal film formed above a substrate, and contains a first ferroelectric crystal having cristallinity when no electric field is applied to the piezoelectric film, and is composed of an inorganic crystalline compound having a property that phase transition of at least a portion of the first ferroelectric crystal to a second ferroelectric crystal of a crystal system different from the first ferroelectric crystal occurs by application of the electric field of a strength of a predetermined level E1 or above, and it is driven under a condition satisfying the expression (1): Emin<E1<Emax, where the minimum electric field applying strength is Emin, the maximum electric field applying strength is Emax, the minimum electric field strength for starting the phase transition from the first ferroelectric crystal to the second ferroelectric crystal is E1. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
