A vibrator includes an electromechanical transducer which is a piezoelectric ceramic made of sodium-potassium niobate metal oxides and whose temperature characteristics of a relative permittivity is 500 [ppm/° C.] or less in absolute value in a temperature range from −40° C. to 170° C., wherein excitation of the electromechanical transducer produces a vibration wave. Another vibrator includes an electromechanical transducer which is a piezoelectric ceramic made of sodium-potassium niobate metal oxides and whose temperature characteristics of a relative permittivity is 390 [ppm/° C.] or less in absolute value in a temperature range from 0° C. to 60° C., wherein excitation of the electromechanical transducer produces a vibration wave.

A vibrator includes an electromechanical transducer which is a piezoelectric ceramic made of sodium-potassium niobate metal oxides and whose temperature characteristics of a relative permittivity is 500 [ppm/° C.] or less in absolute value in a temperature range from −40° C. to 170° C., wherein excitation of the electromechanical transducer produces a vibration wave. Another vibrator includes an electromechanical transducer which is a piezoelectric ceramic made of sodium-potassium niobate metal oxides and whose temperature characteristics of a relative permittivity is 390 [ppm/° C.] or less in absolute value in a temperature range from 0° C. to 60° C., wherein excitation of the electromechanical transducer produces a vibration wave.

A bonded body includes a supporting substrate, silicon oxide layer provided on the supporting substrate, and a piezoelectric material substrate provided on the silicon oxide layer and composed of a material selected from the group consisting of lithium niobate, lithium tantalate and lithium niobate-lithium tantalite. A nitrogen concentration at an interface between the piezoelectric material substrate and silicon oxide layer is higher than a nitrogen concentration at an interface between the silicon oxide layer and the supporting substrate.

Examples disclosed herein relate to an apparatus and method of forming thin film layers on a substrate. A first piezoelectric material layer is deposited on the substrate in a first chamber. The first piezoelectric material layer is formed on the substrate while the substrate is at a first temperature. A second piezoelectric material layer is deposited on the first piezoelectric material layer after cooling the substrate to a second temperature. The second temperature is lower than the first temperature. The first piezoelectric material layer and the second piezoelectric material layer both comprise a first piezoelectric material.

A semiconductor substrate with oxide single crystal heterostructures, to which a sacrificial layer, an epitaxy functional oxide thin film having a perovskite structure and a metal layer are grown on an oxide single crystal substrate, prepared another metal layer on a semiconductor substrate, and bonded the metal layer of the oxide single crystal substrate to the metal layer of the semiconductor substrate to be face each other, and separated the oxide single crystal substrate by selectively etching and removing only the sacrificial layer after the bonding.

A composite substrate includes a final substrate, and a piezoelectric material directly molecularly bonded to the final substrate at a first interface. The piezoelectric material comprises an epitaxial layer, but does not comprise a seed layer. Additional composite substrates include a final substrate, and a piezoelectric material directly molecularly bonded to the final substrate at a first interface. The piezoelectric material comprises an epitaxial layer. The composite substrate further includes a seed layer on which the piezoelectric material has been epitaxially grown. The seed layer is disposed on a side of the epitaxial layer opposite the final substrate. An acoustic wave device comprises such a composite substrate with at least one electrode on a surface of the piezoelectric layer opposite the substrate.

A piezoelectric material composition, a method of manufacturing the same, a piezoelectric device, and apparatus including the piezoelectric device. The piezoelectric device may include a piezoelectric device layer including a first material and a second material surrounded by the first material, a first electrode portion disposed at a first surface of the piezoelectric device layer, and a second electrode portion disposed at a second surface of the piezoelectric device layer opposite to the first surface, wherein the piezoelectric device layer comprises a piezoelectric material composition represented by Chemical Formula 1: 0.96(Na.sub.aK.sub.1-a)(Nb.sub.b(T.sub.1-b))O.sub.3-(0.04-x)MZrO.sub.3-x(Bi.sub.cAg.sub.1-c)ZrO.sub.3+d mol % NaNbO.sub.3, wherein T is Sb or Ta, M is Sr, Ba or Ca, a is 0.4≤a≤0.6, b is 0.90≤b≤0.98, c is 0.4≤c≤0.6, d is 0≤d≤5.0, and x is 0≤x≤0.04 and wherein T is Sb or Ta and M is Sr, Ba, or Ca.

A piezoelectric ceramic transducer includes a tubular body and a metal electrode unit. The tubular body is made of a piezoelectric ceramic material, and includes an inner surrounding surface surrounding an extending central axis thereof and defining an axial through hole, an outer surrounding surface surrounding the inner surrounding surface, and a connecting surface connected between the inner surrounding surface and the outer surrounding surface. Any tangent plane of the connecting surface of the tubular body is not perpendicular to the extending central axis. The metal electrode unit includes a first layer formed on the inner surrounding surface, and a second layer formed on the outer surrounding surface.

A piezoelectric ceramic transducer includes a tubular body and a metal electrode unit. The tubular body is made of a piezoelectric ceramic material, and includes an inner surrounding surface surrounding an extending central axis thereof and defining an axial through hole, an outer surrounding surface surrounding the inner surrounding surface, and a connecting surface connected between the inner surrounding surface and the outer surrounding surface. Any tangent plane of the connecting surface of the tubular body is not perpendicular to the extending central axis. The metal electrode unit includes a first layer formed on the inner surrounding surface, and a second layer formed on the outer surrounding surface.

Some embodiments of the invention relate to an applicator for applying ultrasound energy to a tissue volume, comprising: an array comprising a plurality of ultrasound transducers, the transducers arranged side by side, the transducers configured to emit unfocused ultrasound energy suitable to thermally damage at least a portion of the tissue volume, each of the transducers comprising a coating thin enough so as not to substantially affect heat transfer via the coating to the tissue; and a cooling module configured to apply cooling via the transducers to prevent overheating of a surface of the tissue volume being contacted by the transducers.