A variable capacitance capacitor element according to an embodiment of the present invention comprises: a supporting substrate; a first electrode layer provided on the supporting substrate; a second electrode layer provided opposite to the first electrode layer; and a dielectric layer positioned between the first electrode layer and the second electrode layer. In accordance with an aspect, a main component of the dielectric layer is represented by a composition formula Ba.sub.1−xSr.sub.xTiO.sub.3 (0.5≦x≦0.8), and the first thin film dielectric layer has a thickness of 200 nm or smaller.

A variable capacitance device includes: a supporting substrate having a plurality of variable capacitance elements formed thereon, the plurality of variable capacitance elements being connected in series, wherein each of the plurality of variable capacitance elements has a separate lower electrode, or at least some of the plurality of variable capacitance elements share a lower electrode, thereby forming a plural set of the lower electrodes that serves as the lower electrodes of the respective variable capacitance elements, wherein the variable capacitance device further includes an insulating moisture-resistant film and a conductive adhesive film, and wherein the conductive adhesive film and the insulating moisture-resistant film have a gap in a plan view between at least some of regions where the plural set of the lower electrodes are respectively formed so as to avoid electrical leakage between said at least some of regions through the conductive adhesive film.

A variable capacitance device includes: a supporting substrate having a plurality of variable capacitance elements formed thereon, the plurality of variable capacitance elements being connected in series, wherein each of the plurality of variable capacitance elements has a separate lower electrode, or at least some of the plurality of variable capacitance elements share a lower electrode, thereby forming a plural set of the lower electrodes that serves as the lower electrodes of the respective variable capacitance elements, wherein the variable capacitance device further includes an insulating moisture-resistant film and a conductive adhesive film, and wherein the conductive adhesive film and the insulating moisture-resistant film have a gap in a plan view between at least some of regions where the plural set of the lower electrodes are respectively formed so as to avoid electrical leakage between said at least some of regions through the conductive adhesive film.

Provided is a piezoelectric material filler including alkali niobate compound particles having a ratio (K/(Na+K)) of the number of moles of potassium to the total number of moles of sodium and potassium of 0.460 to 0.495 in terms of atoms and a ratio ((Li+Na+K)/Nb) of the total number of moles of alkali metal elements to the number of moles of niobium of 0.995 to 1.005 in terms of atoms. The present invention can provide a piezoelectric material filler having excellent piezoelectric properties, and a composite piezoelectric material including the piezoelectric material filler and a polymer matrix.

An ink of the formula: 60-80% by weight BaTiO.sub.3 particles coated with SiO.sub.2; 5-50% by weight high dielectric constant glass; 0.1-5% by weight surfactant; 5-25% by weight solvent; and 5-25% weight organic vehicle. Also a method of manufacturing a capacitor comprising the steps of: heating particles of BaTiO.sub.3 for a special heating cycle, under a mixture of 70-96% by volume N.sub.2 and 4-30% by volume H.sub.2 gas; depositing a film of SiO.sub.2 over the particles; mechanically separating the particles; incorporating them into the above described ink formulation; depositing the ink on a substrate; and heating at 850-900° C. for less than 5 minutes and allowing the ink and substrate to cool to ambient in N.sub.2 atmosphere. Also a dielectric made by: heating particles of BaTiO.sub.3 for a special heating cycle, under a mixture of 70-96% by volume N.sub.2 and 4-30% by volume H.sub.2 gas; depositing a film of SiO.sub.2 over the particles; mechanically separating the particles; forming them into a layer; and heating at 850-900° C. for less than 5 minutes and allowing the layer to cool to ambient in N.sub.2 atmosphere.

Provided is a memcapacitor. The memcapacitor includes: a first electrode having a metal-doped perovskite composition; a second electrode disposed on the first electrode; and a dielectric thin film having a perovskite composition, disposed between the first electrode and the second electrode, and having a variable dielectric constant depending on a voltage between the first electrode and the second electrode.

Capacitors with a carbon-based electrode layer in contact with a ferroelectric insulator. The insulator may be a perovskite oxide. Low reactivity of the carbon-based electrode may improve stability of a ferroelectric capacitor. A carbon-based electrode layer may be predominantly carbon and have a low electrical resistivity. A carbon-based electrode layer may be the only layer of an electrode, or it may be a barrier between the insulator and another electrode layer. Both electrodes of a capacitor may include a carbon-based electrode layer, or a carbon-based electrode layer may be included in only one electrode.

An electronic device and a manufacturing method thereof are provided. The manufacturing method of the electronic device includes: providing a substrate; providing an adjustable element, including a liquid crystal layer; and bonding the adjustable element onto the substrate.

A radio-frequency (RF) power variable capacitor capable of operating at, at least, 50 watts in the MHz range. The capacitor has a composite HDK-NDK ceramic dielectric. The HDK (high dielectric constant) component comprises an active matrix of barium strontium titanate, for example. Acoustic resonances are reduced or eliminated by the addition of a metal or metalloid oxide such as magnesium borate (NDK—low dielectric constant), which acts as an acoustic resonance reduction agent (ARRA) in the RF power domain. The acoustic resonances which previously occurred under bias voltage 500 V or 1100 V in prior art RF power variable capacitors are eliminated by the addition of the ARRA.

A radio-frequency (RF) power variable capacitor capable of operating at, at least, 50 watts in the MHz range. The capacitor has a composite HDK-NDK ceramic dielectric. The HDK (high dielectric constant) component comprises an active matrix of barium strontium titanate, for example. Acoustic resonances are reduced or eliminated by the addition of a metal or metalloid oxide such as magnesium borate (NDK—low dielectric constant), which acts as an acoustic resonance reduction agent (ARRA) in the RF power domain. The acoustic resonances which previously occurred under bias voltage 500 V or 1100 V in prior art RF power variable capacitors are eliminated by the addition of the ARRA.