PIEZOELECTRIC ELEMENT AND METHOD FOR MANUFACTURING THE SAME

摘要

Provided is a piezoelectric element including: a substrate; and a lower electrode layer, a piezoelectric layer, and an upper electrode layer which are successively formed on the substrate.  The substrate has a thermal expansion coefficient greater than that of the piezoelectric layer and the piezoelectric layer is a polycrystalline body having an in-plane stress of the compression direction.  This realizes a piezoelectric element including the piezoelectric layer having a high orientation in the polarization axis direction, a high proportionality of a displacement amount against the applied voltage, and a large absolute value of the displacement amount.