Abstract: There is disclosed a method of manufacturing a piezoelectric element including a step of preparing a green sheet A including a portion which becomes a fired piezoelectric body later, by use of a piezoelectric material; a step of joining, to at least one surface of the green sheet A, a green sheet B having an opening in a portion facing the portion which becomes the fired piezoelectric body later, followed by firing to obtain the fired piezoelectric body provided with a reinforcing plate to which the reinforcing plate formed owing to the firing of the green sheet B is attached; and a step of forming a film-like electrode in a portion obtained by the firing of the green sheet A in the fired piezoelectric body provided with the reinforcing plate.

Abstract: A piezoelectric/electrostrictive element having a double-layer structure in which a lower layer electrode film, a lower layer piezoelectric/electrostrictive film, an inner layer electrode film, an upper layer piezoelectric/electrostrictive film and an upper layer electrode film are laminated in this order on a thin portion of a substrate. In the piezoelectric/electrostrictive element, a driving signal is applied between an outer layer electrode film and the inner layer electrode film, whereby the thin portion and a laminate can be subjected to bending vibration. The piezoelectric/electrostrictive film has film thickness distribution in which a film thickness becomes larger in a continuous manner from a center portion of a bending vibration region which is an antinode of a bending first mode toward an edge portion of the bending vibration region which is a node of the bending first mode, along a short side direction of the bending vibration region.

Abstract: A piezoelectric/electrostrictive element having a double-layer structure in which a lower layer electrode film, a lower layer piezoelectric/electrostrictive film, an inner layer electrode film, an upper layer piezoelectric/electrostrictive film and an upper layer electrode film are laminated in this order on a thin portion of a substrate. In the piezoelectric/electrostrictive element, a driving signal is applied between an outer layer electrode film and the inner layer electrode film, whereby the thin portion and a laminate can be subjected to bending vibration. The piezoelectric/electrostrictive film has film thickness distribution in which a film thickness becomes larger in a continuous manner from a center portion of a bending vibration region which is an antinode of a bending first mode toward an edge portion of the bending vibration region which is a node of the bending first mode, along a short side direction of the bending vibration region.

Abstract: There is provided a method for manufacturing a piezoelectric actuator where the planar shape is adjusted by subjecting the piezoelectric body layer located on one of the outer surfaces in the two or more piezoelectric body layers to a polarization treatment to control remnant polarization of the piezoelectric body layer. The piezoelectric actuator is used as a drive portion of a piezoelectric drive type variable capacitor. The variable capacitor has high mechanical strength and excellent reliability for a long period of time. The relation between the displacement amount of the piezoelectric actuator and the capacity of the capacitor is stable, and the variable capacity is wide.

Abstract: The piezoelectric/electrostrictive properties and mechanical durability of a piezoelectric/electrostrictive ceramic can be improved. A piezoelectric/electrostrictive device has a laminated structure in which an electrode film, a piezoelectric/electrostrictive film, an electrode film, an piezoelectric/electrostrictive film, and an electrode film are laminated in the order mentioned on a thin portion of a substrate. The piezoelectric/electrostrictive films are ceramic films with a matrix of perovskite oxide that contains lead (Pb) as an A-site component and nickel (Ni), aluminum (Al), niobium (Nb), zirconium (Zr), and titanium (Ti) as B-site components. The piezoelectric/electrostrictive films are formed by firing as a unit the substrate that contains aluminum oxide and an intermediate coating film of perovskite oxide that contains components other than aluminum so that aluminum oxide is diffused from the substrate to the intermediate coating film.

Abstract: The piezoelectric/electrostrictive properties and mechanical durability of a piezoelectric/electrostrictive ceramic can be improved. A piezoelectric/electrostrictive device has a laminated structure in which an electrode film, a piezoelectric/electrostrictive film, an electrode film, an piezoelectric/electrostrictive film, and an electrode film are laminated in the order mentioned on a thin portion of a substrate. The piezoelectric/electrostrictive films are ceramic films with a matrix of perovskite oxide that contains lead (Pb) as an A-site component and nickel (Ni), aluminum (Al), niobium (Nb), zirconium (Zr), and titanium (Ti) as B-site components. The piezoelectric/electrostrictive films are formed by firing as a unit the substrate that contains aluminum oxide and an intermediate coating film of perovskite oxide that contains components other than aluminum so that aluminum oxide is diffused from the substrate to the intermediate coating film.

Abstract: Piezoelectric/electrostrictive ceramics are provided, which exhibit only a small change in properties after polarization, high insulating properties, and narrow variations in durability. A piezoelectric/electrostrictive element has a laminated structure in which an electrode film, a piezoelectric/electrostrictive film, another electrode film, another piezoelectric/electrostrictive film, and another electrode film are laminated in order of mention on a thin portion of a substrate. The piezoelectric/electrostrictive films are ceramic films that include a perovskite oxide containing lead as an A-site component and magnesium, nickel, niobium, titanium, and zirconium as B-site components. Crystal grains in the piezoelectric/electrostrictive films have a core/shell structure with the shell portion having a higher concentration of nickel than the core portion and with the core portion having a higher concentration of magnesium than the shell portion.

Abstract: In the manufacture of a laminated piezoelectric/electrostrictive element by lamination of a piezoelectric/electrostrictive film and an electrode film containing either platinum or an alloy composed mainly of platinum and having a thickness of 2.0 ?m or less, both or either one of yttrium oxide (Y2O3) and cerium oxide (CeO2) is added to the electrode film or the piezoelectric/electrostrictive film, and the electrode film and the piezoelectric/electrostrictive film are fired simultaneously. This simultaneously achieves a reduced thickness and improved thermal resistance of the electrode film and a reduced change in piezoelectric/electrostrictive properties with time, thereby producing a piezoelectric/electrostrictive element with good initial piezoelectric/electrostrictive properties and with a small change in the piezoelectric/electrostrictive properties with time.

Abstract: A piezoelectric/electrostrictive ceramic composition containing, as a major component, a Pb(Mg1/3Nb2/3)O3—PbTiO3—PbZrO3 ternary solid solution system composition and further containing Ni in an amount of 0.05 to 3.0% by mass in terms of NiO and Si in an amount of 0.003 to 0.01% by mass in terms of SiO2. The piezoelectric/electrostrictive ceramic composition can constitute a piezoelectric/electrostrictive body or a piezoelectric/electrostrictive portion both having an excellent piezoelectric/electrostrictive property and durability even under high-temperature and highly humid conditions.

Abstract: A multilayered piezoelectric/electrostrictive device is provided, including a substrate, a plurality of piezoelectric/electrostrictive portions, and a plurality of electrodes. The piezoelectric/electrostrictive portions and the electrodes are alternately layered on the substrate, and the piezoelectric/electrostrictive portion positioned in the lowermost layer is anchored to the substrate directly or through an electrode. The ratio (?=A/B) of the average particle size (A) (?m) of the piezoelectric/electrostrictive ceramic of the piezoelectric/electrostrictive portion to the thickness (B) (?m) of the piezoelectric/electrostrictive portion satisfies the relationship expressed by “0.02???0.6” in each of the piezoelectric/electrostrictive portions.

Abstract: There is disclosed a piezoelectric device which has a remarkably high piezoelectric characteristic and which is superior in a vibration transmitting property between a substrate and a piezoelectric portion and in which linearity of a flexural displacement with respect to a voltage is high up to a high voltage region and which exhibits a high durability even in a case where the device is used with a large flexural displacement for a long period. The piezoelectric device is provided with: a substrate 2 made of a ceramic; a piezoelectric portion 1 constituted of a piezoelectric porcelain composition containing as a major component a Pb(Mg, Ni)1/3Nb2/3O3—PbZrO3—PbTiO3 ternary solid solution system composition represented by a predetermined formula; and an electrode 3 electrically connected to the piezoelectric portion 1, and the piezoelectric portion 1 is solidly attached onto the substrate 2 directly or via the electrode 3.

Abstract: A piezoelectric/electrostrictive ceramic composition containing, as a major component, a Pb(Mg1/3Nb2/3)O3—PbTiO3—PbZrO3 ternary solid solution system composition and further containing Ni in an amount of 0.05 to 3.0% by mass in terms of NiO and Si in an amount of 0.003 to 0.01% by mass in terms of SiO2. The piezoelectric/electrostrictive ceramic composition can constitute a piezoelectric/electrostrictive body or a piezoelectric/electrostrictive portion both having an excellent piezoelectric/electrostrictive property and durability even under high-temperature and highly humid conditions.

Abstract: A multilayered piezoelectric/electrostrictive device includes a substrate 1, a plurality of piezoelectric/electrostrictive portions 2 and 3, and a plurality of electrodes 4, 5, and 6; the piezoelectric/electrostrictive portions 2 and 3 and the electrodes 4, 5, and 6 being alternately layered on the substrate 1, and the piezoelectric/electrostrictive portion 12 positioned in the lowermost layer being anchored to the substrate 1 directly or through the electrode 4. The ratio &agr; given by the average particle size (A) (&mgr;m) of the piezoelectric/electrostrictive ceramic used for forming the piezoelectric/electrostrictive portion to the thickness (B) (&mgr;m) of the piezoelectric/electrostrictive portion satisfies the relationship expressed by “0.02≦&agr;≦0.6” in each of the piezoelectric/electrostrictive portions 2 and 3.