PIEZOELECTRIC CERAMIC, PIEZOELECTRIC ELEMENT, AND METHOD FOR MANUFACTURING PIEZOELECTRIC CERAMIC

摘要

[Object] A piezoelectric ceramic which has small hysteresis in an output charge output from the piezoelectric ceramic when a load is applied. [Solution] A piezoelectric ceramic 20 includes a pair of main surfaces 2a and 2b that are on opposing sides of a base body 21 and parallel to each other and a side surface 4 continuous to edges 3a and 3b of the pair of main surfaces 2a and 2b. The piezoelectric ceramic contains a layered compound that has a composition formula Bi 4 Ti 3 O 12 ·±MTiO 3 where M is at least one selected from Sr and Ba and ± satisfies 0.1 ‰¤ ± ‰¤ 1, as a main component. The base body 21 includes an outer region 22 that includes the side surface 4 and adjacent regions 4A and 4B of the pair of main surfaces 2a and 2b and an inner region 24 surrounded by the outer region 22. A full width half maximum W A of a peak in a range where a diffraction angle (2¸) is 22.8° to 23.5° in an X-ray diffraction pattern using a Cu-K± ray on the side surface 4 of the outer region 22 is smaller than a full width half maximum W B of a peak in the range where a diffraction angle (2¸) is 22.8° to 23.5° in the X-ray diffraction pattern using the Cu-K± ray on the main surfaces 2a and 2b of the inner region 24.