Tdk Corporation

Yasuhiro Aida

Hitoshi Sakuma

Kazuhiko Maejima

Katsuyuki Kurachi

Yoshitomo Tanaka

Masato Susukida

Mayumi Nakajima

Yuiko Hirose

Hiroshi Chihara

Ryu Ohta

A method of manufacturing a dielectric device includes epitaxially growing a metal film on a substrate, forming a dielectric film on the metal film such that the dielectric film has a preferentially oriented structure, forming a first electrode film having a non-oriented or amorphous structure on the dielectric film, removing the substrate and the metal film from the dielectric film or removing the substrate from the metal film, and forming a second electrode film having a non-oriented or amorphous structure on the dielectric film or the metal film.

Method of manufacturing a dielectric device

A piezoelectric device is provided with a piezoelectric element including a piezoelectric layer exhibiting a polarizability &#x3b3; smaller than 1&#xd7;10(C/(V&#xb7;m)) in the case where an electric field is applied until polarization is saturated and a circuit having a means to set a minimum value of a drive electric field to become larger than a positive coercive electric field of the above-described piezoelectric layer and a means to set a maximum value of the above-described drive electric field to become smaller than (Pm'(maximum value of polarization)&#x2212;Pr&#x2032;(quasi-remanent polarization))/(1&#xd7;10) and, therefore, an object is to drive the piezoelectric element in an electric field range in which maximum piezoelectric characteristics are obtained, improve the characteristics of the piezoelectric device, and enhance the reliability.

Piezoelectric device, piezoelectric actuator, hard disk drive, and inkjet printer apparatus

A thin film piezoelectric element according to the present invention includes a potassium sodium niobate thin film having a structure in which a plurality of crystal grains are present in a film thickness direction; and a pair of electrode films sandwiching the potassium sodium niobate thin film. When the potassium sodium niobate thin film is divided into three regions of the same thickness in the film thickness direction and average crystal grain sizes A, A, and Aof the respective regions are determined, a ratio m/M of the smallest average crystal grain size m among A, A, and Ato the largest average crystal grain size M among A, A, and Ais 10% to 80%. The region having the smallest average crystal grain size m lies next to one of the pair of electrode films.

Thin film piezoelectric element, thin film piezoelectric actuator, thin film piezoelectric sensor, hard drive disk, and inkjet printer device

There are provided a thin-film piezoelectric element including a piezoelectric thin film which has an alkali niobate-based perovskite structure represented by the composition formula (KNaSr)(NbZr)Oand which is preferentially oriented to (001), and a pair of electrode films that sandwich the piezoelectric thin film, a thin-film piezoelectric actuator, and a thin-film piezoelectric sensor each including the thin-film piezoelectric element.

Thin-film piezoelectric element, thin-film piezoelectric actuator, thin-film piezoelectric sensor, hard disk drive, and inkjet printer apparatus

An object is to reduce the leakage current of a piezoelectric element including a potassium-sodium niobate thin film, enhance the reliability of the piezoelectric element and, in addition, enhance the withstand voltage by including a pair of electrodes and a piezoelectric layer sandwiched between the above-described pair of electrode layers, wherein the above-described piezoelectric layer is provided with at least one layer each of first piezoelectric layer which is a potassium-sodium niobate thin film substantially not containing Mn (manganese) and second piezoelectric layer which is a potassium-sodium niobate thin film containing Mn.

Piezoelectric element, piezoelectric actuator, piezoelectric sensor, hard disk drive, and inkjet printer device

A piezoelectric device according to the present invention is provided with a pair of electrode films, a piezoelectric film sandwiched in between the pair of electrode films, and a stress control film which is in direct contact with a surface of at least one of the pair of electrode films, on the side where the electrode film is not in contact with the piezoelectric film, and which has a linear expansion coefficient larger than those of the relevant electrode film and the piezoelectric film.

Piezoelectric device

A piezoelectric element includes, as a piezoelectric layer, a thin film of potassium sodium niobate that is a perovskite compound represented by a general expression ABO, in which Sr (strontium) is substituted on both of an A site and a B site and Mn (manganese) is substituted only on the A site. Accordingly, the piezoelectric element is provided to decrease a leak current of the piezoelectric element using the thin film of potassium sodium niobate, to increase a withstand voltage thereof and to improve piezoelectric characteristics thereof.

A piezoelectric element includes, as a piezoelectric layer, a thin film of potassium sodium niobate that is a perovskite compound represented by a general expression ABO, in which Ta (tantalum) is substituted on both of an A site and a B site. Accordingly, the piezoelectric element is provided to increase a reliability of the piezoelectric element using the thin film of potassium sodium niobate and to improve piezoelectric characteristics thereof.

A thin film piezoelectric device according to the present invention includes a pair of electrode layers and a piezoelectric thin film interposed between the pair of electrode layers, wherein the piezoelectric thin film contains a rare gas element and has a content gradient of the rare gas element in the thickness direction of the piezoelectric thin film.

Thin film piezoelectric device

The displacement as an actuator or the sensitivity as a sensor of a piezoelectric element can be increased and, in addition, the electric power consumption can be reduced by providing a thin film of potassium-sodium niobate, which is a perovskite type compound represented by a general formula ABO, as a piezoelectric layer, wherein a crystal orientation of a crystal structure of potassium-sodium niobate has in-plane fourfold symmetry as a whole piezoelectric layer, where a first axis of rotational symmetry is a thickness direction of the piezoelectric layer.

Piezoelectric element, piezoelectric actuator, piezoelectric sensor, hard disk drive, and ink-jet printer device

A piezoelectric device according to the present invention is provided with a first electrode film, a first nonmetal electroconductive intermediate film provided on the first electrode film, a piezoelectric film provided on the first nonmetal electroconductive intermediate film, a second nonmetal electroconductive intermediate film provided on the piezoelectric film, and a second electrode film provided on the second nonmetal electroconductive intermediate film. A linear expansion coefficient of the first nonmetal electroconductive intermediate film is larger than those of the first electrode film and the piezoelectric film, and a linear expansion coefficient of the second nonmetal electroconductive intermediate film is larger than those of the second electrode film and the piezoelectric film.

Piezoelectric device having first and second non-metal electroconductive intermediate films

A piezoelectric device has a first electrode film, a piezoelectric film provided on the first electrode film, and a second electrode film provided on the piezoelectric film. At least one of the pair of electrode films is composed of an alloy, and a major component of the alloy is a metal selected from the group consisting of Ti, Al, Mg, and Zn.

Piezoelectric device with electrode films and electroconductive oxide film

A solar cell which can increase its open-circuit voltage, short-circuit current, and fill factor (F.F.), thereby enhancing its conversion efficiency is provided. The solar cell of the present invention comprises a p-type semiconductor layer and an n-type semiconductor layer, formed on the p-type semiconductor layer, containing a compound expressed by the following chemical formula (1):ZnOSSe&#x2003;&#x2003;(1)where x&#x2267;0, y&#x3e;0, and 0.2&#x3c;x+y&#x3c;0.65.

Solar cell and method of manufacturing solar cell

A solar cell is provided as one capable of increasing the open voltage when compared with the conventional solar cells. A solar cell according to the present invention has a p-type semiconductor layer containing a group Ib element, a group IIIb element, and a group VIb element, and an n-type semiconductor layer containing a group Ib element, a group IIIb element, a group VIb element, and Zn and formed on the p-type semiconductor layer. A content of the group Ib element in the n-type semiconductor layer is from 15 to 21 at. % to the total number of atoms of the group Ib element, the group IIIb element, the group VIb element, and Zn in the n-type semiconductor layer, and a content of Zn in the n-type semiconductor layer is from 0.005 to 1.0 at. % to the total number of atoms of the group Ib element, the group IIIb element, the group VIb element, and Zn in the n-type semiconductor layer.

Growing community of inventors

Tokyo, Japan

Yasuhiro Aida