Patent ID: 7518293

Claim:
A piezoelectric thin-film element having a lower electrode, a piezoelectric thin-film and an upper electrode arranged on a substrate, wherein said piezoelectric thin-film is a dielectric thin-film composed of a alkaline-niobic oxide represented by (Na x1 K y1 Li z1 ) NbO 3 (0<x 1 <1, 0<y 1 <1, 0≦z 1 <1, x 1 +y 1 +z 1 =1) and having a Perovskite structure, and a base dielectric thin film composed of a alkaline-niobic oxide represented by (Na x2 K y2 Li z2 ) NbO 3 (0<x 2 <1, 0<y 2 <1, 0≦z 2 <1, x 2 +y 2 +z 2 =1) and having a Perovskite structure is provided between said lower electrode and said piezoelectric thin-film.