A piezoelectric laminate and a piezoelectric element have, on a substrate in the following order, a lower electrode layer, and a piezoelectric film containing a perovskite-type oxide. The lower electrode layer includes a first layer arranged in a state of being in contact with the substrate and includes a second layer arranged in a state of being in contact with the piezoelectric film, the first layer contains Ti or TiW as a main component, the second layer is a uniaxial alignment film which contains Ir as a main component and in which the Ir is aligned in a (111) plane, and a half width at half maximum of an X-ray diffraction peak from the (111) plane is 0.3° or more.

A laminated piezoelectric element 10 includes: a laminated body 11 in rectangle shape formed by alternately laminating a plurality of piezoelectric layers 15 and one or more internal electrode(s) 13; a connection electrode 14 connected to one end portion 13a of the internal electrode(s) 13; and an electric field relaxation region 16c or 16d formed discontinuously with regard to the internal electrode(s) 13 in at least one of two corner portions 13c and 13d of the other end portion 13b opposite to the one end portion 13a of the internal electrode(s) 13.

Provided is a lead-free piezoelectric material reduced in dielectric loss tangent, and achieving both a large piezoelectric constant and a large mechanical quality factor. A piezoelectric material according to at least one embodiment of the present disclosure is a piezoelectric material including a main component formed of a perovskite-type metal oxide represented by the general formula (1): Na.sub.x+s(1−y)(Bi.sub.wBa.sub.1−s−w).sub.1−yNb.sub.yTi.sub.1−yO.sub.3 (where 0.84≤x≤0.92, 0.84≤y≤0.92, 0.002≤(w+s)(1−y)≤0.035, and 0.9≤w/s≤1.1), and a Mn component, wherein the content of the Mn is 0.01 mol % or more and 1.00 mol % or less with respect to the perovskite-type metal oxide.

A layered portion includes, at least above an opening, a first single-crystal piezoelectric body layer, a second single-crystal piezoelectric body layer, an intermediate electrode layer, a lower electrode layer, and an upper electrode layer. The first single-crystal piezoelectric body layer includes a material that produces a difference in etching rate between a positive side and a negative side of a polarization charge. The polarization charge of the first single-crystal piezoelectric body layer is negative on a side of the intermediate electrode layer and positive on a side of the lower electrode layer.

A deformation detection sensor is provided that includes a detection electrode, a first ground electrode, a piezoelectric film sandwiched between the detection electrode and the first ground electrode, a substrate on which the detection electrode and a second ground electrode are formed, a wiring connected to the detection electrode, and a joint member that joins the wiring and the detection electrode.

An ultrasonic transducer device for use in an acoustic biometric imaging system, the ultrasonic transducer device comprising: a first piezoelectric element having a first face, a second face opposite the first face, and side edges extending between the first face and the second face; a first transducer electrode on the first face of the first piezoelectric element; a second transducer electrode on the second face of the first piezoelectric element; and a spacer structure leaving at least a portion of the first transducer electrode of the first piezoelectric element uncovered.

A vibration device includes a piezoelectric element, a vibration member to which the piezoelectric element is bonded, and a wiring member connected with the piezoelectric element. A method for vibrating the vibration device includes inputting a signal including a fundamental frequency component to the piezoelectric element through the wiring member, and vibrating the vibration device in a vibration mode that includes the fundamental frequency component and does not approximately include a high order frequency component that is n times (n represents an integer of 2 or more) the fundamental frequency component. The fundamental frequency component is lower than the resonance frequency component of the vibration device.

A thin-film transistor may include an amorphous semiconductor channel layer, an organic material piezoelectric stress gate layer formed adjacent to the amorphous semiconductor channel layer, a source electrode coupled to the organic material piezoelectric stress gate layer, a drain electrode coupled to the organic material piezoelectric stress gate layer and a gate electrode coupled to the organic material piezoelectric stress gate layer. In some embodiments, the amorphous semiconductor channel layer may be amorphous indium gallium zinc oxide. In some embodiments, the organic material piezoelectric stress gate layer may be organic polyvinylidene fluoride. In some embodiments, the amorphous semiconductor channel layer may be formed on a flexible substrate.

A tunable non-reciprocal frequency limiter with an asymmetric micro-electro-mechanical resonator has two independent transducer ports. One port has a film stack including a 10 nm hafnium zirconium oxide (HZO) and another port has a film stack including a 120 nm aluminum nitride (AlN) film. These film stacks are deposited on top of 70 nm single crystal silicon substrate applying CMOS compatible fabrication techniques. The asymmetric transducer architecture with dissimilar electromechanical coupling coefficients force the resonator into mechanical nonlinearity on actuation with transducer having larger coupling. A proof-of-concept electrically-coupled channel filter is demonstrated with two such asymmetric resonators at ˜253 MHz with individual Q.sub.res of ˜870 and a non-reciprocal transmission ratio (NTR) ˜16 dB and BW.sub.3 dB of 0.25%.

There is provided a piezoelectric element including: a substrate; a first electrode formed at a first substrate surface of the substrate in a first direction; a first piezoelectric layer that is formed at the first electrode and that includes a flat surface portion along the first substrate surface and an inclined surface portion inclined with respect to the flat surface portion; a second piezoelectric layer that is formed at the inclined surface portion 170a and whose thickness is smaller than a thickness of the flat surface portion of the first piezoelectric layer; and a second electrode formed at at least the flat surface portion.