Abstract: A piezoelectric actuator includes, in a first direction in which pressure chambers are arranged side by side, an active portion in which a piezoelectric layer is sandwiched between a first electrode and a second electrode in a first area of a vibration plate corresponding to opposite ends of each pressure chamber and does not include the active portion in a second area of the vibration plate corresponding to a center of the pressure chamber. The vibration plate has, in the first direction, a thick-walled portion with a predetermined thickness in the first area and a thin-walled portion thinner than the thick-walled portion in the second area.

Abstract: A piezoelectric body layer of a first area has (100) plane preferential orientation, and a (100) plane orientation ratio of the piezoelectric body layer of a second area is lower than a (100) plane orientation ratio of the piezoelectric body layer of the first area, when one area far from an end portion of a second electrode is the first area, and one area near the end portion of the second electrode is the second area, of two areas of the second electrode in a second direction intersecting a first direction.

Abstract: A piezoelectric element according to the present disclosure includes: a substrate; a first adhesion layer formed on the substrate and containing titanium; at least one of second adhesion layers formed on the substrate and containing titanium oxide; a first electrode formed on the first adhesion layer and the second adhesion layer; a seed layer formed on the first electrode and the substrate and containing titanium; a piezoelectric layer formed on the seed layer; and a second electrode formed on the piezoelectric layer. At least a part of an end portion of the first electrode is formed on the second adhesion layer.

Abstract: A manufacturing method of a piezoelectric element includes: forming a first conductive film on a vibration plate as a substrate; etching a first conductive film; forming a second conductive film on the first conductive film; etching the second conductive film to form a first electrode having a step region as a step formed by the second conductive film and the first conductive film at ends thereof; forming a seed layer as an orientation control layer covering the first electrode by a liquid phase method; forming a piezoelectric film on the seed layer; etching the piezoelectric film to form a piezoelectric body; and forming a second electrode covering the piezoelectric body.

Abstract: A droplet ejection head includes a nozzle plate having a nozzle, a pressure chamber forming substrate having a pressure chamber, a vibration plate, and a piezoelectric element containing potassium, sodium, and niobium and formed on the vibration plate. The piezoelectric element includes a first electrode, a second electrode, and a piezoelectric layer located between the first electrode and the second electrode. A total thickness of the piezoelectric layer, the first electrode, and the second electrode is larger than a thickness of the vibration plate.

Abstract: A piezoelectric element according to the present disclosure includes: a substrate containing silicon; a first electrode formed on the substrate; a piezoelectric layer formed on the first electrode and containing potassium, sodium, and niobium; and a second electrode formed on the piezoelectric layer, in which a first diffusion inhibition layer containing an insulating material is disposed between the substrate and the piezoelectric layer, the piezoelectric layer is continuously formed on a first region which is a surface of the first electrode, a second region which is a surface of the first diffusion inhibition layer, and a third region which is a surface of the substrate, and the third region is between the first region and the second region.

Abstract: A piezoelectric element includes an adhesion layer formed at a vibration plate and containing titanium, a lower electrode formed at the adhesion layer, a diffusion reduction layer formed at the lower electrode and containing iridium, a seed layer formed at the diffusion reduction layer and containing bismuth, a piezoelectric layer formed at the seed layer and containing potassium, sodium, and niobium, and an upper electrode formed at the piezoelectric layer.

Abstract: An electric current based on electric charge produced on the piezoelectric body changes by going through a first path, a second path, a third path, and a fourth path in this order. On the first path, the electric current becomes larger as the voltage becomes higher. On the second path, the electric current becomes smaller as the voltage becomes higher. On the third path, the electric current becomes larger as the voltage becomes higher. On the fourth path, the electric current becomes smaller as the voltage becomes higher.

Abstract: A piezoelectric device includes a diaphragm, a piezoelectric actuator, and an orientation layer between the diaphragm and the piezoelectric layer. The piezoelectric actuator has a first electrode, a piezoelectric layer, and a second electrode, with the first electrode, a piezoelectric layer, and a second electrode on the diaphragm. The orientation layer is a stack of two or more tiers.

Abstract: There is provided a piezoelectric element including: a substrate; a first electrode formed at a first substrate surface of the substrate in a first direction; a first piezoelectric layer that is formed at the first electrode and that includes a flat surface portion along the first substrate surface and an inclined surface portion inclined with respect to the flat surface portion; a second piezoelectric layer that is formed at the inclined surface portion 170a and whose thickness is smaller than a thickness of the flat surface portion of the first piezoelectric layer; and a second electrode formed at at least the flat surface portion.

Abstract: A liquid ejecting head in which a first electrode layer, a piezoelectric layer, and a second electrode layer of a piezoelectric element are laminated, a pressure chamber, which is partitioned by a partition wall, has an elongated shape, in a structure including the diaphragm and the piezoelectric element including an active portion and a non-active portion lateral direction, a first position is a position on an inner side of the active portion when viewed in the thickness direction, a second position is a position on an inner side of the non-active portion and closest to a boundary between the pressure chamber and the partition wall, and EI1/EI2?40, wherein EI1 is a bending rigidity of the active portion at the first position and EI2 is a bending rigidity of the non-active portion at the second position.

Abstract: A method for producing a piezoelectric actuator including forming a vibration plate, forming a first electrode on the vibration plate, forming a piezoelectric layer on the first electrode, and forming a second electrode on the piezoelectric layer, wherein the forming the vibration plate has a single layer forming step including forming a metal layer containing zirconium by a gas phase method, and forming a metal oxide layer by firing the metal layer, the single layer forming step is repeated, thereby forming the vibration plate in which the metal oxide layers are stacked, and the metal oxide layer has a thickness less than 200 nm.

Abstract: A piezoelectric actuator includes, in a first direction in which pressure chambers are arranged side by side, an active portion in which a piezoelectric layer is sandwiched between a first electrode and a second electrode in a first area of a vibration plate corresponding to opposite ends of each pressure chamber and does not include the active portion in a second area of the vibration plate corresponding to a center of the pressure chamber. The vibration plate has, in the first direction, a thick-walled portion with a predetermined thickness in the first area and a thin-walled portion thinner than the thick-walled portion in the second area.

Abstract: A piezoelectric body layer of a first area has (100) plane preferential orientation, and a (100) plane orientation ratio of the piezoelectric body layer of a second area is lower than a (100) plane orientation ratio of the piezoelectric body layer of the first area, when one area far from an end portion of a second electrode is the first area, and one area near the end portion of the second electrode is the second area, of two areas of the second electrode in a second direction intersecting a first direction.

Abstract: A piezoelectric device includes a diaphragm, a piezoelectric actuator, and an orientation layer between the diaphragm and the piezoelectric layer. The piezoelectric actuator has a first electrode, a piezoelectric layer, and a second electrode, with the first electrode, a piezoelectric layer, and a second electrode on the diaphragm. The orientation layer is a stack of two or more tiers.

Abstract: An electric current based on electric charge produced on the piezoelectric body changes by going through a first path, a second path, a third path, and a fourth path in this order. On the first path, the electric current becomes larger as the voltage becomes higher. On the second path, the electric current becomes smaller as the voltage becomes higher. On the third path, the electric current becomes larger as the voltage becomes higher. On the fourth path, the electric current becomes smaller as the voltage becomes higher.

Abstract: A liquid discharge head includes: a nozzle plate provided with a nozzle hole that discharges a liquid; a silicon substrate provided with a pressure chamber that is connected with the nozzle hole; a diaphragm provided on the silicon substrate; and a piezoelectric element that is provided on the diaphragm and that changes a volume of the pressure chamber, where: the diaphragm includes a zirconium oxide layer; the zirconium oxide layer has (?111) preferred orientation; and in X-ray diffraction of the diaphragm, a difference between a position of (002) peak of the zirconium oxide layer and a position of (220) peak of the silicon substrate is 13.26° or more and 13.30° or less.

Abstract: Provided is a liquid discharge head that includes a nozzle plate provided with a nozzle hole that discharges a liquid, a silicon substrate provided with a pressure generating chamber that communicates with the nozzle hole, a vibration plate provided on the silicon substrate, and a piezoelectric element that is provided on the vibration plate and changes a volume of the pressure generating chamber. The piezoelectric element includes a piezoelectric layer including a composite oxide of a perovskite structure containing lead, zirconium, and titanium. A difference between a peak position derived from a (100) surface of the piezoelectric layer and a peak position derived from a (220) surface of the silicon substrate in an X-ray diffraction of the piezoelectric layer is less than 25.00°.

Abstract: There is provided a piezoelectric element including: a substrate; a first electrode formed at a first substrate surface of the substrate in a first direction; a first piezoelectric layer that is formed at the first electrode and that includes a flat surface portion along the first substrate surface and an inclined surface portion inclined with respect to the flat surface portion; a second piezoelectric layer that is formed at the inclined surface portion 170a and whose thickness is smaller than a thickness of the flat surface portion of the first piezoelectric layer; and a second electrode formed at at least the flat surface portion.

Abstract: A method for producing a piezoelectric actuator including forming a vibration plate, forming a first electrode on the vibration plate, forming a piezoelectric layer on the first electrode, and forming a second electrode on the piezoelectric layer, wherein the forming the vibration plate has a single layer forming step including forming a metal layer containing zirconium by a gas phase method, and forming a metal oxide layer by firing the metal layer, the single layer forming step is repeated, thereby forming the vibration plate in which the metal oxide layers are stacked, and the metal oxide layer has a thickness less than 200 nm.