Acutator device and liquid ejecting head including the same

摘要

An actuator device includes a piezoelectric element including a lower electrode (60), a piezoelectric layer (70), and an upper electrode (80) that are displaceably provided in sequence on a substrate. The lower electrode includes a flat portion at a central region thereof and an inclined portion at an end thereof descending toward the substrate. The piezoelectric layer is disposed above the lower electrode and the substrate, and includes a first piezoelectric layer portion constituted by a plurality of columnar crystals (710) extending orthogonally to a surface of the flat portion of the lower electrode, a second piezoelectric layer portion constituted by a plurality of columnar crystals (720) extending orthogonally to a surface of the substrate, and a third piezoelectric layer portion constituted by a plurality of columnar crystals (730) residing on the inclined portion between the first and second piezoelectric layer portions. The columnar crystals of the third piezoelectric layer portion extend orthogonally to a surface of the inclined portion and bend toward the upper electrode so as to extend orthogonally to the surface of the substrate. Grains of the columnar crystals constituting the third piezoelectric layer portion have larger widths than those of grains of the columnar crystals constituting the first and second piezoelectric layer portions at a surface of the piezoelectric layer proximate to the upper electrode.