PIEZOELECTRIC ELEMENT AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To provide a piezoelectric element having sensitivity necessary for flaw detection inside a material. SOLUTION: The piezoelectric element has a lower electrode formed on a base, a zinc oxide thin film formed on the surface of the lower electrode film and an upper electrode formed on the surface of the zinc oxide thin film. A material having > (13×10<6> kg/m<2> s) acoustic impedance is used as the base and a strength ratio between the a-axis [1000]0 and c-axis [0001] of the zinc oxide based upon X-ray diffraction measurement is within the range of 0