Liquid ejecting head, liquid ejecting apparatus and actuator device

An actuator device comprising:

• a first electrode;
• a piezoelectric material layer formed above the first electrode and having a perovskite structure;
• and
• a second electrode formed above the piezoelectric material layer,
• wherein the piezoelectric material layer has a monoclinic structure, and
• wherein an angle formed between the direction of an electric field generated between the first electrode and the second electrode and a direction of a polarization moment of the piezoelectric material layer is greater than an angle formed between the direction of the electric field and the orientation of the polarization moment of the piezoelectric material layer at the point that the piezoelectric constant of the piezoelectric material layer reaches a local maximum level.

A liquid ejecting apparatus comprising:

• a liquid ejecting head including:
• a fluid channel forming substrate having a pressure generating chamber formed therein which communicates with a nozzle opening that ejects a liquid droplet;
• and
• a piezoelectric element having, a first electrode, a piezoelectric material layer that is provided on the first electrode, the piezoelectric material layer having a perovskite structure indicated by a general formula:
• ABO3, and a second electrode formed on the piezoelectric material layer opposite to the first electrode;
• and
• and a driving unit that applies a voltage across the first electrode and the second electrode so as to generate an electric field in a predetermined direction to the piezoelectric element so as to drive the liquid ejecting head,
• wherein the piezoelectric material layer has a monoclinic structure, and an angle formed between the direction of an electric field generated between the first electrode and the second electrode and an orientation of a polarization moment of the piezoelectric material layer is greater than an angle formed between the direction of the electric field when the piezoelectric constant of the piezoelectric material layer reaches a maximum level and the orientation of the polarization moment of the piezoelectric material layer, and
• wherein a displacement amount of the piezoelectric material layer increases in accordance with an increase in the number of times the driving unit drives the liquid ejecting head.