Piezoelectric film and ink jet head and angular velocity sensor using the same

An ink jet head comprising:

• a piezoelectric film having a piezoelectric layer sandwiched between a first electrode and a second electrode;
• a vibration layer bonded to the piezoelectric film;
• and
• a pressure chamber member having a pressure chamber for storing ink and bonded to a surface of the vibration layer opposite to a surface to which the piezoelectric film is bonded, wherein
• the vibration layer is bonded to the piezoelectric film so that the vibration layer is displaceable in its film thickness direction according to a deformation of the piezoelectric film produced by a piezoelectric effect,
• the vibration layer and the pressure chamber member are bonded to each other so that a volumetric capacity of the pressure chamber changes according to a displacement of the vibration layer and so that the ink in the pressure chamber is ejected according to a change in the volumetric capacity of the pressure chamber,
• the piezoelectric layer is a (NaxBiy)TiO0.5x+1.5y+2—BaTiO3 layer (0.30≦x≦0.46 and 0.51≦y≦0.62) with a (110) orientation only and the (NaxBiy)TiO0.5x+1.5y+2—BaTiO3 layer has composition around a Morphotropic Phase Boundary.

An angular velocity sensor comprising:

• a substrate having a vibration part;
• and
• a piezoelectric film bonded to the vibration part and having a piezoelectric layer sandwiched between a first electrode and a second electrode, wherein
• the piezoelectric layer is a (NaxBiy)TiO0.5x+1.5y+2—BaTiO3 layer (0.30≦x≦0.46 and 0.51≦y≦0.62) with a (110) orientation only and the (NaxBiy)TiO0.5x+1.5y+2—BaTiO3 layer has composition around a Morphotropic Phase Boundary, and
• one of the first electrode and the second electrode selected therefrom is composed of an electrode group including a drive electrode for applying a driving voltage that oscillates the vibration part to the piezoelectric layer and a sense electrode for measuring a deformation of the vibration part caused by an angular velocity applied to the oscillating vibration part.