Patent ID: 8063543

Claim:
A piezoelectric thin film element, comprising: a substrate; a lower electrode; a piezoelectric thin film; and an upper electrode, wherein the lower electrode, the piezoelectric thin film and the upper electrode are formed on the substrate, and wherein the piezoelectric thin film comprises: a polycrystal thin film including crystal grains; an alkali niobium oxide based perovskite structure represented by a general formula: (K 1-x Na x )NbO 3, wherein 0.4<x<0.7; a film thickness of not less than 1 μm and not more than 10 μm; a columnar structure configured by the crystal grains, a majority of the crystal grains including a length in a cross-section direction thereof longer than in a plane direction of the substrate; and an average crystal grain size of not less than 0.1 μm and not more than 1.0 μm in the plane direction of the substrate.