US Patent 7291520 Piezoelectric element and liquid jet head using the piezoelectric element

Provided are a piezoelectric element and a liquid-jet head using the same, in which favorable crystallinity can be obtained with improved uniformity, breakage of a piezoelectric film can be prevented, thereby providing stable displacement properties. The piezoeletric element includes a lower electrode, a piezoelectric film formed on the lower electrode, and an upper electrode formed on the piezoelectric film. The piezoelectric film in turn includes a lower layer portion having column crystals, and an upper layer portion having column crystals which are continuous from those in the lower layer portion and having sizes larger than those in the lower layer portion.