| 摘要 |
A piezoelectric element which includes an undercoat layer and a piezoelectric material layer that have been formed on a substrate, the undercoat layer being for controlling the crystallinity of the piezoelectric material layer. The piezoelectric material layer is configured of crystals having an ABO 3 -type structure which contains at least Pb at the A sites. In the undercoat layer, the surface that faces the interface with the substrate contains, at the A sites, at least Pb and another substance that differs in content from that in the piezoelectric material layer and, at the B sites, substances having a content ratio different from that in the piezoelectric material layer. Due to this, the undercoat layer has a given crystal structure that has better crystallinity than the piezoelectric material layer. In the layer of the undercoat layer which is located upper than the surface that faces the interface with the substrate, the content of the other substance contained in the A sites of the undercoat layer gradually changes from the surface that faces the interface with the substrate to the surface that faces the interface with the piezoelectric material layer, while the content ratio of the substances contained in the B sites gradually changes. Thus, the composition of the undercoat layer comes closer to that of the piezoelectric material layer. |
