Patent ID: 8035281

Claim:
A sensor for detecting a physical quantity, comprising: a piezoelectric thin film device including a lower electrode, a piezoelectric thin film and an upper electrode; and a voltage detecting device connected between the lower and upper electrodes of the piezoelectric thin film device; wherein the piezoelectric thin film is formed of an alkali niobium oxide-based perovskite material expressed by (K 1-x Na x )NbO 3 (0<x<1); and wherein a (001) KNN plane diffraction peak of the piezoelectric thin film indicates an angle 2θ from 22.1° to 22.5° in an X-ray diffraction 2θ/θ measurement to a surface of the piezoelectric thin film, and the (001) KNN plane diffraction peak occupies 80% or more of diffraction peaks of the piezoelectric thin film.