Abstract: Provided is a vehicle undercover having well-balanced rigidity. A vehicle undercover 10 is provided with: a plate-shaped body 12 made of a porous material such as a fiber body or a foam; and a support body 14 supporting the plate-shaped body 12. The support body 14 has a groove-shaped first frame part 20 having a horizontal plate 20a and vertical plates 20b and 20b extending from both edges of the horizontal plate 20a. Further, the support body 14 has a second frame part 22 provided across the first frame part 20 and having a smaller dimension of protrusion toward the inside of a vehicle than the first frame part 20.

Abstract: A liquid ejecting apparatus includes: a liquid ejecting head that includes a flow path formation substrate in which a pressure chamber communicating with a nozzle is formed, a vibration plate, and a piezoelectric actuator having a first electrode, a piezoelectric layer, and a second electrode; and a drive unit that supplies a drive signal for driving the piezoelectric actuator, in which the piezoelectric actuator includes an active portion, the active portion is extended from an edge portion, which is a region other than a central portion of a region facing the pressure chamber, to the outside of the pressure chamber, and the drive signal includes a contraction element that contracts the pressure chamber from a reference volume of the pressure chamber when no electric field is applied to the piezoelectric layer, and an expansion element that expands the pressure chamber contracted by the contraction element.

Abstract: A recording head includes a pressure chamber and a piezoelectric actuator configured to change a volume of the pressure chamber. The piezoelectric actuator includes a vibration plate forming one wall surface of the pressure chamber, a lower electrode formed on the vibration plate, a piezoelectric body formed on the lower electrode, and an upper electrode formed on the piezoelectric body and the vibration plate. When viewed from a ±Z direction orthogonal to the vibration plate, the lower electrode and the piezoelectric body do not overlap a central portion of the pressure chamber, when viewed from the ±Z direction, the lower electrode, the piezoelectric body, and the upper electrode overlap an end portion of the pressure chamber, and when viewed from the ±Z direction, the upper electrode overlaps the central portion of the pressure chamber.

Abstract: A piezoelectric device including a flow path forming substrate in which pressure chambers are formed, a diaphragm, and piezoelectric actuators. Active portions, each having a piezoelectric layer interposed between a first electrode and a second electrode, are each, in plan view, provided from an edge portion opposing the pressure chamber to a portion outside the pressure chamber, and a ratio of a film thickness of the piezoelectric layer to a film thickness of the diaphragm is 4.7 or less.

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 element includes a piezoelectric layer formed as a stacked structure of first, second, and third piezoelectric films. The first piezoelectric film is formed on a first electrode. The second piezoelectric film is formed on the first piezoelectric film. The third piezoelectric film is formed on the second piezoelectric film. Each of the first, second, and third piezoelectric films includes potassium, sodium, and niobium. A second electrode is formed on the piezoelectric layer. A concentration of sodium in the first piezoelectric film is greater than a concentration of sodium in the second piezoelectric film. The concentration of sodium in the second piezoelectric film is greater than a concentration of sodium in the third piezoelectric film.

Abstract: A piezoelectric element includes a first electrode; a piezoelectric layer, placed on or above the first electrode, containing potassium, sodium, niobium, titanium, and oxygen; and a second electrode placed on or above the piezoelectric layer.

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: A recording head includes a pressure chamber and a piezoelectric actuator configured to change a volume of the pressure chamber. The piezoelectric actuator includes a vibration plate forming one wall surface of the pressure chamber, a lower electrode formed on the vibration plate, a piezoelectric body formed on the lower electrode, and an upper electrode formed on the piezoelectric body and the vibration plate. When viewed from a ±Z direction orthogonal to the vibration plate, the lower electrode and the piezoelectric body do not overlap a central portion of the pressure chamber, when viewed from the ±Z direction, the lower electrode, the piezoelectric body, and the upper electrode overlap an end portion of the pressure chamber, and when viewed from the ±Z direction, the upper electrode overlaps the central portion of the pressure chamber.

Abstract: A liquid ejecting apparatus includes: a liquid ejecting head that includes a flow path formation substrate in which a pressure chamber communicating with a nozzle is formed, a vibration plate, and a piezoelectric actuator having a first electrode, a piezoelectric layer, and a second electrode; and a drive unit that supplies a drive signal for driving the piezoelectric actuator, in which the piezoelectric actuator includes an active portion, the active portion is extended from an edge portion, which is a region other than a central portion of a region facing the pressure chamber, to the outside of the pressure chamber, and the drive signal includes a contraction element that contracts the pressure chamber from a reference volume of the pressure chamber when no electric field is applied to the piezoelectric layer, and an expansion element that expands the pressure chamber contracted by the contraction element.

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 device including a flow path forming substrate in which pressure chambers are formed, a diaphragm, and piezoelectric actuators. Active portions, each having a piezoelectric layer interposed between a first electrode and a second electrode, are each, in plan view, provided from an edge portion opposing the pressure chamber to a portion outside the pressure chamber, and a ratio of a film thickness of the piezoelectric layer to a film thickness of the diaphragm is 4.7 or less.

Abstract: A piezoelectric element includes a substrate, a first electrode formed on the substrate, a piezoelectric layer, which is a layered structure of a plurality of piezoelectric films each containing potassium, sodium, and niobium, formed on the first electrode, and a second electrode formed on the piezoelectric layer. A sodium concentration in the piezoelectric layer has a Na local maximum value, which is a local maximum value of the sodium concentration, in a first piezoelectric film, which is among the plurality of piezoelectric films, in the vicinity of the first electrode, a sodium concentration gradient decreasing from the Na local maximum value toward the second electrode, and a Na local minimum value, which is a local minimum value of the sodium concentration, near a boundary between the first piezoelectric film and a second piezoelectric film formed immediately above the first piezoelectric film.

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: 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 piezoelectric element including a first electrode provided above a substrate, a piezoelectric layer provided above the first electrode, containing potassium, sodium, and niobium, and having a perovskite structure, and a second electrode provided above the piezoelectric layer. In a case where the piezoelectric layer is divided into two portions at a center thereof in a thickness direction, the piezoelectric layer includes a first portion on the first electrode side and a second portion on the second electrode side. The piezoelectric layer includes line defects. A density of the line defects in the second portion is higher than a density of the line defects in the first portion.

Abstract: A vibrating plate is provided between a substrate and a piezoelectric element formed of electrodes and a piezoelectric layer and includes a first layer which is formed of a silicon oxide and a second layer which is formed of a ceramic having a Young's modulus larger than that of the silicon oxide. Under the condition in which the following expression (1) has a constant value, where in the expression (1), Ev1, dv1, Ev2, and dv2 represent Young's modulus of the first layer, the thickness thereof, Young's modulus of the second layer, and the thickness thereof, Ev1×dv12+Ev2×dv22??(1) when the combination of dv1 and dv2 which sets the value of the following expression (2) in a range of from the minimum value to +2% thereof is represented by (Dv1, Dv2), Ev1×dv13+Ev2×dv23??(2) the thickness of the first layer and the thickness of the second layer are represented by Dv1 and Dv2.

Abstract: A piezoelectric element includes: a first electrode containing crystal grains; a piezoelectric layer which contains potassium, sodium, and niobium and which is provided above the first electrode; and a second electrode provided above the piezoelectric layer, and the average grain diameter of the crystal grains is less than 550 nm.

Abstract: A piezoelectric element includes a piezoelectric layer formed as a stacked structure of first, second, and third piezoelectric films. The first piezoelectric film is formed on a first electrode. The second piezoelectric film is formed on the first piezoelectric film. The third piezoelectric film is formed on the second piezoelectric film. Each of the first, second, and third piezoelectric films includes potassium, sodium, and niobium. A second electrode is formed on the piezoelectric layer. A concentration of sodium in the first piezoelectric film is greater than a concentration of sodium in the second piezoelectric film. The concentration of sodium in the second piezoelectric film is greater than a concentration of sodium in the third piezoelectric film.