Piezoelectric element, ink jet recording head and producing method for piezoelectric element

A piezoelectric element comprising a vibrating plate, a lower electrode, a piezoelectric film and an upper electrode laminated in this order, wherein

• the lower electrode, the upper electrode and the piezoelectric film are formed of a perovskite type oxide while the vibrating plate is formed of a perovskite type metal oxide,
• the piezoelectric element includes (i) between the vibrating plate and the lower electrode, a region where a substance constituting the vibrating plate and a substance constituting the lower electrode are mixed, (ii) between the lower electrode and the piezoelectric film, a region where a substance constituting the lower electrode and a substance constituting the piezoelectric film are mixed, and (iii) between the piezoelectric film and the upper electrode, a region where a substance constituting the piezoelectric film and a substance constituting the upper electrode are mixed,
• a junction interface is substantially absent between the vibrating plate and the lower electrode, between the lower electrode and the piezoelectric film, and between the piezoelectric film and the upper electrode,
• each of the regions (i), (ii) and (iii) has a perovskite crystal structure, and
• each of the lower electrode and the upper electrode is independently formed by M1RuO3 (M1 being at least one selected from a group consisting of Sr, Ba and Ca) or Sr(1-x)M2(x)CoO3 (M2 being at least one selected from a group consisting of La, Pr, Sm and Nd;
• and x satisfying 0≦x<1).