A micro-electro-mechanical systems (MEMS) sensor includes a substrate, a diaphragm portion and a piezoelectric film. The diaphragm portion is located at the substrate. The piezoelectric film is located on the diaphragm portion. The piezoelectric film is made of scandium aluminum nitride. A carbon concentration of the piezoelectric film is 2.5 atomic percent or less while an oxygen concentration of the piezoelectric film is 0.35 atomic percent or less.

A micro-electro-mechanical systems (MEMS) sensor includes a substrate, a diaphragm portion and a piezoelectric film. The diaphragm portion is located at the substrate. The piezoelectric film is located on the diaphragm portion. The piezoelectric film is made of scandium aluminum nitride. A carbon concentration of the piezoelectric film is 2.5 atomic percent or less while an oxygen concentration of the piezoelectric film is 0.35 atomic percent or less.

A piezoelectric element includes, on a base, an underlying layer for controlling crystallinity of a piezoelectric layer, and the piezoelectric layer. The piezoelectric layer includes a crystal with an ABO.sub.3-type structure having at least Pb at A sites. In the underlying layer, an interface-with-the-base side is configured including at least Pb and another substance with a different composition rate from that of the piezoelectric layer at the A sites, and a substance with a different composition ratio from that of the piezoelectric layer at B sites. In a layer above the interface-with-the-base side in the underlying layer, the composition rate of the other substance included at the A sites of the underlying layer progressively changes and also the composition ratio of the substance included at the B sites progressively changes, from the interface-with-the-base side toward the interface-with-the-piezoelectric-layer side to approach the composition of the piezoelectric layer.

A layered solid element includes a ferroelectric layer of a crystalline material Li.sub.1−x(Nb.sub.1−yTa.sub.y).sub.1+xO.sub.3+2x−z which has X- or 33° Y-orientation with respect to a substrate of the layered solid element. The ferroelectric layer is grown epitaxially from a buffer layer having of one of the chemical formulae L.sub.kNi.sub.rO.sub.1.5.Math.(k+r)+w or L.sub.n+1Ni.sub.nO.sub.3n+1+δ, where L is a lanthanide element. Such layered solid element may form a thin-film bulk acoustic resonator and be useful for integrated electronic circuits such as RF-filters, or guided optical devices such as integrated optical modulators.

A layered solid element includes a ferroelectric layer of a crystalline material Li.sub.1−x(Nb.sub.1−yTa.sub.y).sub.1+xO.sub.3+2x−z which has X- or 33° Y-orientation with respect to a substrate of the layered solid element. The ferroelectric layer is grown epitaxially from a buffer layer having of one of the chemical formulae L.sub.kNi.sub.rO.sub.1.5.Math.(k+r)+w or L.sub.n+1Ni.sub.nO.sub.3n+1+δ, where L is a lanthanide element. Such layered solid element may form a thin-film bulk acoustic resonator and be useful for integrated electronic circuits such as RF-filters, or guided optical devices such as integrated optical modulators.

A chamber of a hybrid chemical and physical vapor deposition (HybCPVD) provides high-quality and uniform films on relatively large multiple wafers per growth run at reasonably high deposition rates using a scalable high-throughput process. Transition-metal-alloyed III-N single-crystalline and textured thin films are epitaxially and non-epitaxially deposited on a suitable substrate (of, for example, silicon or a metal such as aluminum or titanium) by providing a mixture of various gases in a deposition/growth chamber. The precursors for the chemical reactions include vapor phase of elements of transition metals, vapor phase of chlorides, and vapor phase of hydride. This growth technique provides high growth rate and high-quality epitaxial materials.

A Method for producing a microsystem (1) with pixels includes: producing a thermal silicon oxide layer on the surface of a silicon wafer as a base layer (5) by oxidation of the silicon wafer; producing a silicon oxide thin layer on the base layer as a carrier layer (6)by thermal deposition; producing a platinum layer on the carrier layer by thermal deposition, whereby an intermediate product is produced; cooling the intermediate product to room temperature; pixel-like structuring of the platinum layer by removing surplus areas of the platinum layer, whereby bottom electrodes (8, 12) of the pixels (7, 8) are formed in pixel shape on the carrier layer in remaining areas; removing material on the side of the silicon wafer facing away from the base layer, so a frame (3) remains and a membrane (4) formed by the base layer and the carrier layer is spanned by the frame.

A piezoelectric actuator includes a piezoelectric element that includes a piezoelectric unit including a ferroelectric, which has an asymmetric bipolar P-E curve, a capacitor connected to the piezoelectric unit in series, and a resistor connected to the capacitor in series and connected to the ferroelectric in parallel; and a drive unit that inputs a drive waveform Vd, which includes a DC offset component of which polarity is opposite to polarization of the ferroelectric, to the piezoelectric element to drive the piezoelectric element. A value of a coercive electric field Ec.sub.1, a value of a coercive electric field Ec.sub.2, the capacitance C.sub.s of the capacitor, the capacitance C.sub.pz of the ferroelectric, combined resistance R.sub.p of the resistance of the resistor and the resistance of the ferroelectric, and a fundamental angular frequency ω of the drive waveform satisfy Expressions I to III, wherein

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A piezoelectric element exhibiting a small leakage current density and high reliability as compared with a KNN thin film piezoelectric element in the related art is provided. The piezoelectric element is characterized by including a lower electrode, a piezoelectric layer primarily made from potassium-sodium niobate, which is a perovskite type compound represented by a general formula ABO.sub.3, and an upper electrode, wherein the piezoelectric layer is present between the lower electrode and the upper electrode, and the piezoelectric layer has the value determined by dividing the maximum value of intensity of a diffraction peak, where the angle of 2θ is within the range of 21.1°≦2θ≦23.4° in the X-ray diffraction pattern (2θ/θ), by the intensity of a diffraction peak, where 2θ is within the range of 30.1°≦2θ≦33.3°, of 0.04 or less.

The present invention aims to provide a piezoelectric composition and a piezoelectric element. In the piezoelectric composition, the main component is represented by the following formula with a perovskite type structure,
(Bi.sub.(0.5x+y+z)Na.sub.0.5x).sub.m(Ti.sub.(x+0.5y)Mg.sub.0.5yMe.sub.z)O.sub.3
wherein, 0.05≦x≦0.7, 0.01≦y≦0.7, 0.01≦z≦0.6, 0.75≦m≦1.0, x+y+z=1 and the transition metal element Me is any one or more selected from the group consisting of Mn, Cr, Fe and Co.