It is an object to provide a ferroelectric thin film having much higher ferroelectric properties than conventional Sc-doped ferroelectric thin film constituted by aluminum nitride and also having stability when applied to practical use, and also to provide an electronic device using the same.

There are provided a ferroelectric thin film represented by a chemical formula M1.sub.1-XM2.sub.XN, wherein M1 is at least one element selected from Al and Ga, M2 is at least one element selected from Mg, Sc, Yb, and Nb, and X is within a range of 0 or more and 1 or less, and also an electronic device using the same.

An electronic device may include a first electrode, a first magnetostrictive layer coupled to the first electrode, a plurality of alternating ferromagnetic and insulating layers stacked above the first magnetostrictive layer, a second electrode electrically coupled to an intermediate ferromagnetic layer in the stack of ferromagnetic and insulating layers, a second magnetostrictive layer above the stack of ferromagnetic and insulating layers, and a third electrode electrically coupled to the second magnetostrictive layer. At least one ferromagnetic layer below the intermediate ferromagnetic layer may be switchable between different polarization states responsive to a first voltage applied across the first and second electrodes, and at least one ferromagnetic layer above the intermediate ferromagnetic layer may be switchable between different polarization states responsive to a second voltage applied across the second and third electrodes.

An electronic device may include a first electrode, a first magnetostrictive layer coupled to the first electrode, a plurality of alternating ferromagnetic and insulating layers stacked above the first magnetostrictive layer, a second electrode electrically coupled to an intermediate ferromagnetic layer in the stack of ferromagnetic and insulating layers, a second magnetostrictive layer above the stack of ferromagnetic and insulating layers, and a third electrode electrically coupled to the second magnetostrictive layer. At least one ferromagnetic layer below the intermediate ferromagnetic layer may be switchable between different polarization states responsive to a first voltage applied across the first and second electrodes, and at least one ferromagnetic layer above the intermediate ferromagnetic layer may be switchable between different polarization states responsive to a second voltage applied across the second and third electrodes.

A transducer includes first and second piezoelectric layers made of corresponding different first and second piezoelectric materials and three or more electrodes, implemented in two or more conductive electrode layers. The first piezoelectric layer is sandwiched between a first pair of electrodes and the second piezoelectric layer is sandwiched between a second pair of electrodes. The first and second pairs of electrodes contain no more than one electrode that is common to both pairs.

A transducer includes first and second piezoelectric layers made of corresponding different first and second piezoelectric materials and three or more electrodes, implemented in two or more conductive electrode layers. The first piezoelectric layer is sandwiched between a first pair of electrodes and the second piezoelectric layer is sandwiched between a second pair of electrodes. The first and second pairs of electrodes contain no more than one electrode that is common to both pairs.

A method is provided to measure viscosity of an analyte using a microfluidic piezoelectric sensor including a channel on an active area of a piezoelectric resonator substrate. The microfluidic piezoelectric sensor is driven so that the active area of the piezoelectric resonator substrate generates shear motion in a direction of shear motion displacement that is parallel with respect to a first surface of the piezoelectric resonator substrate. A high shear-rate viscosity of the analyte is determined based on a shift in resonance of the microfluidic piezoelectric sensor while driving the microfluidic piezoelectric sensor with the analyte in the channel. A low shear-rate viscosity of the analyte is determined by detecting flow of the analyte through the channel based on tracking shifts in resonance of the microfluidic piezoelectric sensor. Related sensors are also discussed.

A method is provided to measure viscosity of an analyte using a microfluidic piezoelectric sensor including a channel on an active area of a piezoelectric resonator substrate. The microfluidic piezoelectric sensor is driven so that the active area of the piezoelectric resonator substrate generates shear motion in a direction of shear motion displacement that is parallel with respect to a first surface of the piezoelectric resonator substrate. A high shear-rate viscosity of the analyte is determined based on a shift in resonance of the microfluidic piezoelectric sensor while driving the microfluidic piezoelectric sensor with the analyte in the channel. A low shear-rate viscosity of the analyte is determined by detecting flow of the analyte through the channel based on tracking shifts in resonance of the microfluidic piezoelectric sensor. Related sensors are also discussed.

A piezoelectric sound generation component is provided that includes a piezoelectric vibration plate, a case with a case body and a lid that accommodates the piezoelectric vibration plate in an inner space formed by the case body and the lid, and a pin terminal provided to the lid so that the pin terminal is abutted on the piezoelectric vibration plate. The case body has a first top wall and a first circumferential wall. The lid has a second top wall, a second circumferential wall, and a protruding portion that contacts the first circumferential wall of the case body. The protruding portion has a first surface that is abutted on a contact surface, facing the first top wall, of the first circumferential wall and a second surface that couples the first surface to the second circumferential wall and is separated from the first circumferential wall.

[Object] To provide a technology such as a piezoelectric coil having higher energy conversion efficiency.

[Solving Means] A piezoelectric coil according to the present technology includes a coil-like core material and a plurality of band-like piezoelectric materials. The plurality of piezoelectric materials is helically wound around the core material so as to be alternately arranged along the core material.

An acoustic wave device includes a piezoelectric substrate made of LiNbO.sub.3 or LiTaO.sub.3 and including first and second main surfaces that face each other, an IDT electrode provided on the first main surface of the piezoelectric substrate, and a Li.sub.2CO.sub.3 layer provided on the second main surface of the piezoelectric substrate.