PIEZOELECTRIC ELEMENT AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To provide a piezoelectric element which is improved in piezoelectric characteristics and dielectric strength characteristic, and its manufacture. SOLUTION: A substrate 1 where a lower electrode 3 is formed is coated at least once with 1st sol for forming a PZT film 4 and then coated with 2nd sol containing more lead than the 1st sol, and then heat treatment is carried out at least once at a specified temperature to obtain a piezoelectric element having a piezoelectric film with a small difference in the presence amount of lead along the film thickness. The 2nd sol has composition enabling the formation of a piezoelectric film with a perovskite crystalline structure represented as a general formula Ax By O3 and can be so prepared that the content of the substance constituting the A site of the 1st sol is larger than the content of the substance which constitutes the A site of the 2nd sol. In the formula, A is Pb, La, or Ca and B is Ti, Zn, Mg, or Nb or their combination.