Patent attributes
Disclosed are a piezoelectric element in which crystallinity of a piezoelectric layer is improved, and which has uniform characteristics of the piezoelectric layer, a liquid-jet head using the piezoelectric element as well as a liquid-jet apparatus. The piezoelectric element includes: a lower electrode provided to one surface side of a substrate; a piezoelectric layer which is made of a piezoelectric material containing lead (Pb), zirconium (Zr) and titanium (Ti), and which is provided above the lower electrode; and an upper electrode provided above the piezoelectric layer, and in the piezoelectric element, a relative permittivity of the piezoelectric layer is 750 to 1500 and a coercive electric field of the piezoelectric layer is 10 to 40 kV/cm.