Patent ID: 8100515

Claim:
A multilayer piezoelectric actuator comprising: a multilayered body comprising a plurality of piezoelectric ceramic layers containing a PZT phase as a main crystal phase; and an electrode layer containing Ag, which is disposed at least one of on the surface and in the interior of the multilayered body, wherein a lattice constant c of c-axis of the PZT phase is 0.4085 nm to 0.4100 nm, and a ratio of the lattice constant c of the c-axis of the PZT phase and a lattice constant a of a-axis, namely, the ratio c/a, is 1.011 or more; a second phase containing Ag different from the PZT phase is not substantially contained in the piezoelectric ceramic layer; and a Zn 2 SiO 4 phase is contained at grain boundaries of the PZT phase, and a Pb 2 SiO 4 phase is not substantially contained at the grain boundaries of the PZT phase.