Patent ID: 8084924

Claim:
A piezoelectric/electrostrictive film element, comprising: a ceramic substrate; electrodes; and a piezoelectric/electrostrictive substance formed on the ceramic substrate or on one of the electrodes disposed on the ceramic substrate, the piezoelectric/electrostrictive substance including a plurality of curved crystal grains that, when viewed in cross-section taken along a plane perpendicular to the particle thickness, have a wavy structure composed of wavy grain boundaries, the wavy grain boundaries including concave portions and convex portions, the concave portions and the convex portions mating with convex portions and concave portions of adjacent crystal grains, respectively, wherein the curvature of the crystal grains, defined by the length of a first straight line between adjacent triple points of grain boundaries divided into the maximum length of a perpendicular line drawn from the first straight line to the grain boundary between the adjacent triple points, is at least 0.1.