Piezoelectric device, liquid discharge head, liquid discharge device, and method for manufacturing piezoelectric device

A piezoelectric device comprising:

• a piezoelectric body;
• a vibration plate that vibrates when the piezoelectric body is driven;
• a first electrode positioned between the piezoelectric body and the vibration plate;
• and
• a second electrode positioned to be separated from the first electrode by the piezoelectric body, wherein
• the piezoelectric body includes an active portion that is a part sandwiched between the first electrode and the second electrode in a first direction along a thickness direction of the piezoelectric body,
• when a change in capacitance with respect to a change in a voltage applied along a second direction orthogonal to the first direction regards as a dC/dV value,
• the dC/dV value at a first position in the first direction is larger than 0,
• the dC/dV value at a second position in the first direction is larger than 0 and different from the dc/dV value at the first position, the second position being different from the first position in the first direction, and
• a change width of the dC/dV value from one end of the active portion on a side of the first electrode to the other end of the active portion on a side of the second electrode in the first direction is 10% or less.