Patent ID: 8193687

Claim:
A piezoelectric/electrostrictive ceramics sintered body comprising: a perovskite type oxide serving as a main crystal phase, the perovskite type oxide containing at least one type of element selected from the group consisting of Li, Na and K as A site constituent elements, and at least one type of element selected from the group consisting of Nb and Ta as B site constituent elements, wherein a diffuse scattering intensity ratio is equal to or lower than 0.5, the diffuse scattering intensity ratio being a ratio of an intensity of diffuse scattering by a lattice-strained layer present near a domain wall to a sum of an X-ray diffraction intensity of a first lattice plane and an X-ray diffraction intensity of a second lattice plane different in interplanar spacing from the first lattice plane due to crystallographic symmetry reduction.