Abstract: A piezoelectric element includes: a first electrode and a second electrode; and a piezoelectric layer provided between the first electrode and the second electrode, where: the piezoelectric layer contains a complex oxide having a perovskite structure and including potassium, sodium, and niobium; on a cross-section of the piezoelectric layer, a standard deviation of values that are obtained by normalizing sodium atom concentrations in eight regions by an average value of the sodium atom concentrations in the eight regions is 0.140 or less; each of the regions includes a central line of the piezoelectric layer; each of the regions is a square having a size in a thickness direction of the piezoelectric layer and a size in a direction orthogonal to the thickness direction of 150 nm; and the eight regions are aligned in the direction orthogonal to the thickness direction.

Abstract: A piezoelectric element includes a first electrode provided at a base body, a piezoelectric layer provided at the first electrode and containing a composite oxide that contains potassium, sodium, and niobium and that has a perovskite structure, and a second electrode provided at the piezoelectric layer, wherein the first electrode is a platinum layer, the first electrode is preferentially oriented to (111), and the first electrode has an average crystal grain diameter of 200 nm or more.

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: A piezoelectric element includes: a first electrode provided on a base; a piezoelectric layer provided on the first electrode and containing a complex oxide which has a perovskite structure and contains potassium, sodium, and niobium; and a second electrode provided on the piezoelectric layer, in which the first electrode contains platinum, the first electrode is (111) preferentially oriented, and a platinum atom contained in the first electrode is bonded to an oxygen atom at an interface between the first electrode and the piezoelectric layer.

Abstract: A piezoelectric element includes a first electrode, a second electrode, and a piezoelectric layer. The piezoelectric layer is provided between the first electrode and the second electrode, and is formed of a perovskite type oxide which contains potassium, sodium, niobium, and manganese. In the piezoelectric layer, a proportion of an A-site constituent element of the perovskite type oxide is smaller than a proportion of a B-site constituent element thereof. In XRD measurement of the piezoelectric layer, two or more peaks derived from the perovskite type oxide are provided in a range of 44°<2?<48°, and an intensity ratio (X/Y) between a peak X having the highest intensity among the peaks, and a peak Y having the lowest intensity satisfies the following expression. 2.

Abstract: A piezoelectric element includes: a first electrode and a second electrode; and a piezoelectric layer provided between the first electrode and the second electrode, where: the piezoelectric layer contains a complex oxide having a perovskite structure and including potassium, sodium, and niobium; on a cross-section of the piezoelectric layer, a standard deviation of values that are obtained by normalizing sodium atom concentrations in eight regions by an average value of the sodium atom concentrations in the eight regions is 0.140 or less; each of the regions includes a central line of the piezoelectric layer; each of the regions is a square having a size in a thickness direction of the piezoelectric layer and a size in a direction orthogonal to the thickness direction of 150 nm; and the eight regions are aligned in the direction orthogonal to the thickness direction.

Abstract: A piezoelectric element includes a substrate; a first electrode formed above the substrate; a piezoelectric layer which contains a composite oxide having a perovskite crystal structure and which is formed above the first electrode; and a second electrode formed above the piezoelectric layer, and the amount of carbon contained in the substrate is 0.26 to less than 14.00 percent by atom.

Abstract: A piezoelectric element including a first electrode provided above a base body, a first piezoelectric layer provided so as to be in contact with the base body and cover the first electrode, a second piezoelectric layer provided above the first piezoelectric layer, and a second electrode provided above the second piezoelectric layer, wherein the first piezoelectric layer includes a composite oxide that contains potassium and niobium and that has a perovskite-type structure containing potassium as amain component at an A-site, the second piezoelectric layer includes a composite oxide that contains potassium, sodium, and niobium and that has a perovskite-type structure, and the first piezoelectric layer has a higher potassium atomic concentration (atm %) than the second piezoelectric layer.

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 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 material contains: a first component which is a rhombohedral crystal in a single composition, has a Curie temperature Tc1, and is a lead-free-system composite oxide having a perovskite-type structure; a second component which is a crystal other than the rhombohedral crystal in a single composition, has a Curie temperature Tc2<Tc1, and is a lead-free-system composite oxide having a perovskite-type structure; and a third component which is a crystal other than the rhombohedral crystal in a single composition similar to the second component, has a Curie temperature Tc3?Tc1, and is a lead-free-system composite oxide that has a perovskite-type structure and is different from the second component. When a molar ratio of the third component to the sum of the second component and the third component is ? and ?×Tc3+(1??)×Tc2 is Tc4, |Tc4?Tc2|?50° C.

Abstract: A piezoelectric element includes a first electrode, a piezoelectric layer formed of a first piezoelectric film which is formed on the first electrode and which includes potassium, sodium, and niobium and a plurality of second piezoelectric films which are formed on the first piezoelectric film and which include potassium, sodium, and niobium, and a second electrode formed on the piezoelectric layer, in which the piezoelectric layer is a stack of a plurality of piezoelectric films, the first piezoelectric film has a thickness of 30 nm to 70 nm, a concentration of sodium in each of the piezoelectric films is along a gradient in the film thickness direction with the first electrode side being high and the second electrode side being low.

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 piezoelectric element includes a substrate; a first electrode formed above the substrate; a piezoelectric layer which contains a composite oxide having a perovskite crystal structure and which is formed above the first electrode; and a second electrode formed above the piezoelectric layer, and the amount of carbon contained in the substrate is 0.26 to less than 14.00 percent by atom.

Abstract: A piezoelectric element includes a first and a second electrode, a piezoelectric layer between the first electrode and the second electrode, and an orientation control layer between the first electrode and the piezoelectric layer. The orientation control layer contains perovskite complex oxide containing potassium, sodium, calcium, and niobium and preferentially oriented in the (100) plane.

Abstract: A piezoelectric element includes a first electrode, a piezoelectric layer which is formed on the first electrode by using a solution method, and is formed from compound oxide which has a perovskite structure in which potassium, sodium, and niobium are provided, and a second electrode which is provided on the piezoelectric layer. The piezoelectric layer has a peak derived from a (200) plane and a peak derived from a (002) plane in an X-ray diffraction pattern obtained by ?-2? measurement.

Abstract: There is provided a piezoelectric element which includes a first electrode which is formed on a substrate, a piezoelectric layer which is formed on the first electrode, and is formed from a compound oxide having an ABO3 type perovskite structure in which potassium (K), sodium (Na), niobium (Nb), and manganese (Mn) are provided, and a second electrode which is formed on the piezoelectric layer. The manganese includes bivalent manganese (Mn2+), trivalent manganese (Mn3+), and tetravalent manganese (Mn4+). A molar ratio (Mn2+/Mn3++Mn4+) of the bivalent manganese to a sum of the trivalent manganese and the tetravalent manganese is equal to or greater than 0.31.

Abstract: There is provided a piezoelectric element which includes a first electrode, a piezoelectric layer which is formed on the first electrode by using a solution method, and is formed from a compound oxide having a perovskite structure in which potassium, sodium, and niobium are provided, and a second electrode which is provided on the piezoelectric layer. A cross-sectional SEM image of the piezoelectric layer is captured at a magnification of 100,000. When evaluation is performed under a condition in which a measured value in a transverse direction is set to 1,273 nm, two or more voids are included in the piezoelectric layer, a difference between the maximum value and the minimum value among diameters of the voids to be largest in a film thickness direction is equal to or smaller than 14 nm, and the maximum value is equal to or smaller than 24 nm.

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 piezoelectric element includes a first electrode, a second electrode, and a thin piezoelectric layer. The thin piezoelectric layer is provided between the first electrode and the first electrode, and is formed of a perovskite type compound oxide which contains potassium, sodium, and niobium. In the piezoelectric layer, in an X-ray diffraction pattern obtained by ??2? measurement, peaks derived from a (002) plane and a (200) plane are provided in a range in which 2? is from 45° to 47°, a peak position of the peak on a high angle side among the peaks satisfies 46.0°?2??46.5°, and a difference of 2? between the peak on the high angle side and the peak on a low angle side is greater than 0.60°.