Patent ID: 7145285

Claim:
A piezoelectric element comprising: a first electrode film; a piezoelectric layered film composed of a first piezoelectric film formed on said first electrode film and a second piezoelectric film that is formed on said first piezoelectric film and is controlled in crystal orientation thereof by said first piezoelectnc film; and a second electrode film formed on said second piezoelectric film, wherein each of said first piezoelectric film and said second piezoelectric film is an aggregate of columnar grains grown unidirectionally along a thickness direction of said piezoelectric layered film, a columnar grain of said second piezoelectric film has a larger cross-sectional diameter than a columnar grain of said first piezoelectric film, and a ratio l/d of a thickness l of said piezoelectric layered film to the cross-sectional diameter d of said columnar grain of said second piezoelectric film is not less than 20 and not more than 60.