Piezoelectric element with underlying layer to control crystallinity of a piezoelectric layer, and piezoelectric device, inkjet head, and inkjet printer including such piezoelectric element

A piezoelectric element comprising:

• on a base, an underlying layer for controlling crystallinity of a piezoelectric layer, wherein the piezoelectric layer comprises a crystal with an ABO3-type structure comprising at least Pb at A sites of the piezoelectric layer;
• and
• the underlying layer comprising:
• a first layer lying above an interface-with-the-base side of the first layer is configured to have an ABO3-type structure and comprises at least Pb and a first substance with a different composition rate from that of the piezoelectric layer at A sites, and a second substance with a different composition rate from that of the piezoelectric layer at B sites, and accordingly has a predetermined crystal structure with a higher degree of crystallinity than the piezoelectric layer;
• and
• a second layer sandwiched between the first layer and the piezoelectric layer, wherein the second layer is configured to have an ABO3-type structure and approaches a composition of the piezoelectric layer by progressively changing a composition rate of the first substance at A sites of the second layer and also the composition rate of the second substance included at B sites of the second layer, in a direction from the interface-with-the-base side toward an interface-with-the-piezoelectric-layer side.