An ultrasonic transducer includes a backing element, an active element overlying the backing layer, and a matching element overlying the active element, the matching element having an inner surface that contacts the active element and an outer surface with a non-homogeneous texture and/or material composition. The matching element may be formed by subtractive or deposition techniques.

An elastic wave device includes a high acoustic velocity film configured such that a bulk wave propagates at a higher acoustic velocity than an elastic wave that propagates in a piezoelectric film, a low acoustic velocity film configured such that a bulk wave propagates at a lower acoustic velocity than a bulk wave that propagates in the piezoelectric film is laminated on the high acoustic velocity film, the piezoelectric film is laminated on the low acoustic velocity film, and an IDT electrode is laminated on one surface of the piezoelectric film. In an upper structure section, an energy concentration ratio of a main mode which is an elastic wave is not less than about 99.9% and an energy concentration ratio of a high order mode which is spurious is not more than about 99.5%.

A piezoelectric thin-film element includes a substrate, a lower electrode layer formed on the substrate, a piezoelectric thin-film layer that is formed on the lower electrode layer and includes potassium sodium niobate having a perovskite structure represented by the composition formula of (K.sub.1-xNa.sub.x)NbO.sub.3 (0.4x0.7), and an upper electrode layer formed on the piezoelectric thin-film layer. The piezoelectric thin-film layer is formed such that a value of (Ec.sup.+Ec.sup.+)/2 is not less than 10.8 kV/cm and a value of (Pr.sup.+Pr.sup.+)/2 is not more than 2.4 C/cm.sup.2 where Ec.sup. and Ec.sup.+ are intersection points of a polarization-electric field hysteresis loop and the x-axis indicating an electric field and Pr.sup. and Pr.sup.+ are intersection points of the polarization-electric field hysteresis loop and the y-axis indicating polarization.

A piezoelectric film containing (K,Na)NbO.sub.3 as the main component, wherein, when a surface of the piezoelectric film was observed in a field view within a specified range, a plurality of first crystals and a plurality of second crystals are arranged in the surface of the piezoelectric film, wherein, the first crystal has a slender shape orientating toward the first orientation along the surface, and the second crystal has a slender shape orientating toward the second orientation which crosses with the first orientation along the surface.

Provided is a piezoelectric element including: a first electrode; a piezoelectric layer which is provided over the first electrode; and a second electrode provided on a side of the piezoelectric layer opposite to the first electrode, in which the second electrode includes a first layer which is provided on the piezoelectric layer side, and a second layer which is provided on a side of the first layer opposite to the piezoelectric layer, and the second layer does not contain platinum and covers an end portion of the first layer.

A piezoelectric device includes a substrate; an insulating layer provided on the substrate; a lower electrode layer provided on the insulating layer; a piezoelectric structure provided on the lower electrode layer, the piezoelectric structure including at least one conductive layer and multiple piezoelectric layers sandwiching the conductive layer, the conductive layer having the same crystal structure as that of the piezoelectric layers; and an upper electrode layer provided on the piezoelectric structure.

A piezoelectric film having a porosity between 20 and 40%, a thickness ranging from tens of microns to less than a few millimeters can be used to form an ultrasonic transducer UT for operation in elevated temperature ranges, that emit pulses having a high bandwidth. Such piezoelectric films exhibit greater flexibility allowing for conformation of the UT to a surface, and obviate the need for couplings or backings. Furthermore, a method of fabricating an UT having these advantages as well as better bonding between the piezoelectric film and electrodes involves controlling porosity within the piezoelectric film.

A piezoelectric element includes a first electrode, a second electrode, and a piezoelectric layer provided between the first and second electrodes. In the piezoelectric element, the piezoelectric layer is made from a perovskite composite oxide represented by Pb(Ni, Nb, Zr, Ti)O.sub.3 and the total of the Ni and Nb contents in the perovskite composite oxide is not less than 1 [mol %] and not more than 5 [mol %] based on a total content of elements contained in a B site.

Provided is a sheet-shape electrostatic sound pressure-electrical signal conversion device that is three-dimensionally deformable and has a low drive voltage. The sound pressure-electrical signal conversion device includes a polymer sheet sandwiched between a pair of electrodes facing each other, the polymer sheet is a dielectric film, at least one of the electrodes includes an insulating flexible substrate having a plurality of through-holes and a plurality of conductive fibers having one end fixed to the flexible substrate with a pressure sensitive adhesive, electrical conduction in an in-plane direction is formed by contact between the conductive fibers, the conductive fibers are vibrated by giving an electrical signal to the pair of electrodes or the conductive fibers are vibrated by receiving sound pressure to cause the pair of electrodes to output an electrical signal.

A piezoelectric ceramic electronic component that includes a piezoelectric ceramic body including at least one piezoelectric ceramic layer; and a plurality of electrodes on a surface or inside of the piezoelectric ceramic body and arranged so that the at least one piezoelectric ceramic layer is sandwiched between adjacent electrodes of the plurality of electrodes. The at least one piezoelectric ceramic layer is a ceramic sintered body containing a potassium sodium niobate-based compound and Mn. When the at least one piezoelectric ceramic layer sandwiched between the adjacent electrodes is divided into three equal parts in a thickness direction to sequentially define a first region, a second region, and a third region between the adjacent electrodes, a second Mn concentration in the second region is higher than a first Mn concentration in the first region and a third Mn concentration in the third region.