Piezoelectric element and liquid ejection head

Abstract

A piezoelectric element is a piezoelectric element including a piezoelectric layer including a plurality of layers and a pair of electrodes disposed with the piezoelectric layer interposed between the electrodes. The piezoelectric layer is formed of lead zirconate titanate. ΔH is 21% or less when an average value, a maximum value, and a minimum value of a content of hydrogen contained in one central layer of the layers are defined as H(ave), H(max), and H(min), respectively, and a larger one of absolute values of (H(max)−H(ave))/H(ave)) and (H(min)−H(ave))/H(ave)) is defined as ΔH as a change rate of the content of hydrogen.

Dependencies are inferred from the claim text.