Patent ID: 9136460
Filing Date: 2015-09-15
Classification: B06B,B41J,G02B,H01L,H02N,H04N

Abstract:
1. A piezoelectric element comprising: a first electrode; a piezoelectric material portion; and a second electrode, wherein the piezoelectric material portion is made of a piezoelectric ceramic that includes a perovskite-type metal oxide including barium titanate and Mn and that has residual polarization, wherein the piezoelectric material portion has a measurement surface extending in a direction that crosses a direction of the residual polarization of the piezoelectric ceramic, and, after the measurement surface has been polished to have a surface roughness of 200 nm or less, the measurement surface has a (002)/(200) X-ray diffraction intensity ratio of 1.0 or more at room temperature, wherein a ratio c/a of a c-axis lattice constant c to an a-axis lattice constant a of the piezoelectric ceramic at room temperature satisfies 1.004≦c/a≦1.010, and wherein a half-width of a (002) diffraction peak of the measurement surface at room temperature is 1.2° or less.