Abstract: An acoustic wave device includes a support substrate having a thickness in a first direction, a piezoelectric layer on the support substrate, and an interdigital transducer electrode on the piezoelectric layer and including first and second electrode fingers extending in a second direction crossing the first direction. The second electrode fingers face the first electrode fingers in a third direction orthogonal or substantially orthogonal to the second direction. The support substrate and the piezoelectric layer include a hollow therebetween at a position at least partially overlapping the interdigital transducer electrode in the first direction. At least one through hole penetrates the piezoelectric layer at a position not overlapping the interdigital transducer electrode in the first direction, and the through hole communicates with the hollow. A reinforcing support extends inside the hollow in a region overlapping the hollow and not overlapping the first and second electrode fingers.

Abstract: An acoustic wave device includes a support, a piezoelectric layer on the support, and an IDT electrode including first and second electrode fingers. When a thickness of the piezoelectric layer is d and a center-to-center distance of the first and second electrode fingers adjacent to each other is p, d/p is less than or equal to about 0.5. When an imaginary line connecting tips of the first electrode fingers is an envelope, a direction in which the envelope extends and the direction of the Y-axis intersect each other, and about 9°?|?|?about 14° is satisfied, where |?| is an absolute value of a slant angle ?. The slant angle ? is an angle of a corner defined by the direction in which the envelope extends and the direction of the Y-axis and is an angle other than 0°.

Abstract: An acoustic wave device includes a high acoustic velocity structure, a low acoustic velocity layer on the high acoustic velocity structure, a piezoelectric layer directly or indirectly on the low acoustic velocity layer, and an electrode on the piezoelectric layer. The low acoustic velocity layer is made of a dielectric material having a lower Young's modulus than silicon oxide, or includes the dielectric material as a main component.

Abstract: A piezoelectric thin film includes a piezoelectric element and a substrate supporting the piezoelectric element. The piezoelectric element includes a piezoelectric thin film and first and second electrodes opposing each other with the piezoelectric thin film interposed therebetween. The piezoelectric thin film has a first-electrode-side content of each of aluminum and scandium higher than a second-electrode-side content thereof and a first-electrode-side content of nitrogen lower than a second-electrode-side content thereof.

Abstract: An acoustic wave device includes a support substrate, a dielectric film, a piezoelectric layer, and an excitation electrode. The piezoelectric layer includes first and second main surfaces. The second main surface is on a side including the dielectric film. A cavity portion is provided in the dielectric film and overlaps at least a portion of the excitation electrode in plan view. The dielectric film includes a side wall surface facing the cavity portion and including an inclined portion inclined so that a width of the cavity portion decreases with increasing distance away from the piezoelectric layer. The inclined portion includes at least an end portion on a side including the piezoelectric layer, in the side wall surface. When an angle between the inclined portion and the second main surface of the piezoelectric layer is defined as an inclination angle ?, the inclination angle ? is from about 40° to about 80° inclusive.

Abstract: A piezoelectric device includes a piezoelectric single crystal body with a homogeneous polarization state and of which at least a portion flexurally vibrates, an upper electrode on an upper surface of the piezoelectric single crystal body, a lower electrode on a lower surface of the piezoelectric single crystal body, and a supporting substrate below the piezoelectric single crystal body. A recess extends from a lower surface of the supporting substrate toward the lower surface of the piezoelectric single crystal body.

Abstract: An acoustic wave device includes a support substrate, a piezoelectric layer overlapping the support substrate viewed in a first direction, a functional electrode on at least a first main surface of the piezoelectric layer, and a wiring electrode connected to the functional electrode. A space is provided on a second main surface side opposite to the first main surface of the piezoelectric layer. The space is covered with the piezoelectric layer, the wiring electrode covers a portion of the functional electrode, and an air gap or an insulating film is provided between the functional electrode and the wiring electrode in a region where the functional electrode is covered with the wiring electrode.

Abstract: An acoustic wave device includes a piezoelectric layer and electrodes including at least a pair of electrodes on a first main surface, facing each other in a second direction crossing a first direction, and adjacent to each other. At least three or more of the electrodes are arranged in the second direction. The electrodes include at least two electrodes having different film thicknesses from each other. The electrodes include at least two electrodes having the same or substantially the same film thickness and being adjacent to each other.

Abstract: An acoustic wave device includes a support substrate, a piezoelectric layer on the support substrate, a functional electrode on the piezoelectric layer, and first and second electrode films on the piezoelectric layer, facing each other, and having different electric potentials from each other. When a region between the first and second electrode films in a plan view is an inter-electrode film region, and a region overlapping with the first electrode film or the second electrode film in a plan view is an electrode film underlying region, a thickness of the piezoelectric layer in at least a portion of the inter-electrode film region is smaller than a thickness of the piezoelectric layer in the electrode film underlying region.

Abstract: A collation device includes a light source unit; a camera unit that receives light emitted from the light source unit and reflected in a collation area of an object to acquire a photographed image of the collation area; and a processor configured to, by executing a program: detect a positional relationship between the light source unit and the camera unit by using the photographed image, and notify of a collation result between the photographed image and a registered image prepared in advance by using the positional relationship.

Abstract: An acoustic wave device includes a piezoelectric film and an IDT electrode on the piezoelectric film. The IDT electrode includes first and second busbars, at least one first electrode finger, and at least one second electrode finger. When an overlap region is defined as a region in which the first and second electrode fingers overlap each other in an acoustic wave propagation direction, points A2, B2, C2, and D2, defined as follows, are all outside the cavity when, at the points A2, B2, C2, and D2, xa>about 25 ?m, ya>about 25 ?m, xb>about 25 ?m, yb>about 25 ?m, xc>about 25 ?m, yc>about 25 ?m, xd>about 25 ?m, and yd>about 25 ?m.

Abstract: An acoustic wave device includes a piezoelectric layer and first and second electrodes. The first and second electrodes face each other in a direction intersecting with a thickness direction of the piezoelectric layer. The acoustic wave device uses a bulk wave of a thickness-shear primary mode. A material of the piezoelectric layer is lithium niobate or lithium tantalate. The piezoelectric layer is on a first main surface of the silicon substrate. The acoustic wave device further includes a trap region on a side of a second main surface of the piezoelectric layer.

Abstract: An elastic wave device in which a recess is provided on an upper side of a support, a piezoelectric thin film covers the recess, and an IDT electrode is provided on an upper surface of the piezoelectric thin film. A plate wave of an S0 mode or SH0 mode is used. A plurality of grooves are provided in the upper surface or lower surface of the piezoelectric thin film at a portion of the piezoelectric thin film that is positioned on a hollow section.

Abstract: An elastic wave device includes a piezoelectric film made of lithium niobate or lithium tantalate, and a first electrode finger and a second electrode finger opposing each other in a direction intersecting a thickness direction of the piezoelectric film. When an average thickness of the piezoelectric film is d and a distance between centers of the first electrode finger and the second electrode finger is p, d/p is about 0.5 or less. The first electrode finger and the second electrode finger are connected to the first and second bus bars, respectively. The first and second bus bars include corner portions. At least one of corner portions of the first and second bus bars is outside a cavity portion when viewed in plan view.

Abstract: An acoustic wave device includes a piezoelectric layer that is made of lithium niobate or lithium tantalate, and a plurality of pairs of electrodes opposed to each other in a direction intersecting with a thickness direction of the piezoelectric layer, in which a bulk wave in a thickness shear primary mode is used or d/p is about 0.5 or lower when a thickness of the piezoelectric layer is d and a distance between centers of mutually adjacent electrodes among the plurality of pairs of electrodes is p. The plurality of pairs of electrodes include at least one pair of first electrodes of a first acoustic wave resonator and at least one pair of second electrodes of a second acoustic wave resonator. A direction orthogonal to a longitudinal direction of the second electrodes in the second acoustic wave resonator is inclined at an angle that is greater than 0° and smaller than 360° with respect to a direction orthogonal to a longitudinal direction of the first electrodes in the first acoustic wave resonator.

Abstract: An elastic wave device includes a supporting substrate including an upper surface including a recessed portion, a piezoelectric thin film on the supporting substrate to cover the recessed portion of the supporting substrate, an IDT electrode on a main surface of the piezoelectric thin film, the main surface being adjacent to the supporting substrate, and an intermediate layer on a main surface of the piezoelectric thin film, the main surface being remote from the supporting substrate. A space is defined by the supporting substrate and the piezoelectric thin film. The IDT electrode faces the space. Through holes are provided in the piezoelectric thin film and the intermediate layer to extend from a main surface of the intermediate layer to the space, the main surface being remote from the piezoelectric thin film. The elastic wave device further includes a cover member on the intermediate layer and covering opening ends of the through holes.

Abstract: An acoustic wave device includes a support substrate, a piezoelectric layer, and an IDT electrode. The piezoelectric layer is over the support substrate. The IDT electrode is on the piezoelectric layer, and includes a plurality of electrode fingers. An intersecting width of the plurality of electrode fingers is equal to or smaller than about 5?.

Abstract: A piezoelectric device includes a piezoelectric body at least a portion of which can bend and vibrate, an upper electrode on an upper surface of the piezoelectric body and in which distortion of a crystal lattice is reduced as a distance from the upper surface of the piezoelectric body increases, a lower electrode on a lower surface of the piezoelectric body and in which distortion of a crystal lattice is reduced as a distance from the upper surface of the piezoelectric body increases, and a support substrate below the piezoelectric body, in which a recess extending from a lower surface of the support substrate toward the lower surface of the piezoelectric device is provided.

Abstract: A method for producing a metal powder provided on the surface thereof with a glassy thin film, wherein a glassy substance is produced in the vicinity of the surface of the metal powder by spray pyrolysis from a solution that contains a thermally decomposable metal compound and a glass precursor that produces a glassy substance that does not form a solid solution with the metal produced from the metal compound by thermal decomposition, so as to form the metal powder provided on the surface thereof with the glassy thin film. The metal includes a base metal as a major component, and the solution contains 5 to 30 mass %, as the mass % with reference to the overall solution, of a reducing agent that is soluble in the solution and exhibits a reducing activity during the aforementioned step of heating.

Abstract: A method for producing a metal powder provided on the surface thereof with a glassy thin film, wherein a glassy substance is produced in the vicinity of the surface of the metal powder by spray pyrolysis from a solution that contains a thermally decomposable metal compound and a glass precursor that produces a glassy substance that does not form a solid solution with the metal produced from the metal compound by thermal decomposition, so as to form the metal powder provided on the surface thereof with the glassy thin film. The glass precursor is prepared such that the melting temperature TmM of the metal and the liquid phase temperature TmG of the mixed oxide of the glassy substance satisfy the following formula (1): ?100 [° C.]?(TmM?TmG)?500 [° C.]??(1).