Murata Manufacturing Co., Ltd.

Osaka University

National Institute for Materials Science

Murata Manufacturingco., Ltd.

Masahiko Kimura

Akira Ando

Takuya Sawada

Koichi Hayashi

Hirozumi Ogawa

Kosuke Shiratsuyu

Shinichiro Kawada

Tadahiro Minamikawa

Tomoyuki Ogawa

Yasunari Miwa

Shota Ushiba

Hiroaki Kaida

Jiro Inoue

Hiroshi Takagi

Nobuyuki Wada

Toshikazu Takeda

Tetsuo Uchikoshi

Yoshio Sakka

Toru Nagae

Tohru Suzuki

Tatsuya Yamaguchi

Ayumi Shinagawa

Naruto Miyakawa

Takao Ono

Kazuhiko Matsumoto

A virus detection system is provided for receiving electrical signals that change quantitatively based on an amount of virus, via a communication line, from a measuring device equipped with graphene sensors that output the electrical signals that change quantitatively based on the amount of virus contained in samples collected from subjects and that associate the electrical signals with identification information for each subject. The virus detection further analyzes the amount of the virus contained in the samples collected from each of the subjects based on changes in the electrical signals outputted from the graphene sensors; and sends, via the communication line, analysis results on the amount of virus contained in the samples collected from each of the subjects to the communication terminal pre-registered to each subject.

Virus detection system, virus detection method, and virus detection program

A graphene transistor includes a graphene layer including at least one sheet of graphene, a drain electrode and a source electrode each electrically connected to the graphene layer, a charge donor on at least one main surface of the graphene layer, the charge donor including an impurity charge, and a counter ion having a charge with a sign different from a sign of the impurity charge.

Graphene transistor and method of manufacturing same

Piezoelectric oriented ceramics containing a Pb(Ti, Zr)O-based compound having a high degree of orientation not lower than 0.64, which was calculated with the Lotgering method based on an X-ray diffraction pattern in a prescribed cross-section thereof, and having a sintered density not lower than 85% of a theoretical density.

Piezoelectric oriented ceramics and method of manufacturing the same

An additive that contains an emulsion binder resin substantially free of non-emulsion binder resin, such as an emulsion acrylic resin, is mixed into a ceramic raw material powder containing, as its main constituent, a perovskite-type compound to form a ceramic slurry. Then, an orientational ceramic is prepared by subjecting the slurry to a forming process while simultaneously or sequentially applying a magnetic field and drying the slurry. An orientational ceramic, even formed from a substance which has small magnetic anisotropy, such as PZT, is obtained.

Method for producing orientational ceramic, orientational ceramic, and ceramic electronic component

A method for manufacturing a piezoelectric element that includes a piezoelectric ceramic body containing an internal electrode. The piezoelectric ceramic body is mainly made of a perovskite complex oxide containing an alkali metal niobate-based compound containing at least one element selected from among K, Li, and Na. The internal electrode is made of a base metal material, such as Ni or Cu. The piezoelectric element is produced by co-sintering the internal electrode and the piezoelectric ceramic body in a reducing atmosphere.

Method of manufacturing a piezoelectric element

A piezoelectric ceramic composition includes a main component represented by general formula {(PbCaSr) {Ti(NiNb)}O}, wherein 0&#x2266;x&#x2266;0.2 (preferably 0&#x2266;x&#x2266;0.15), 0&#x2266;y&#x2266;0.2 (preferably 0&#x2266;y&#x2266;0.1), 0.05&#x2266;x+y&#x2266;0.2, and 0.02&#x2266;z&#x2266;0.1. Furthermore, a Mn component is preferably present in an amount of 1.0 part by weight or less (excluding zero) (more preferably 0.05 to 1.0 part by weight) in terms of MnCOwith respect to 100 parts by weight of the main component. A piezoelectric element includes a piezoelectric ceramic body composed of this piezoelectric ceramic composition. Firing can be performed at a low temperature of about 1,100&#xb0; C. The piezoelectric element has a high Curie point Tc, can withstand solder reflow treatment, and achieves satisfactory piezoelectric properties.

Piezoelectric ceramic compositions and piezoelectric elements

A piezoelectric ceramic composition contains main components represented by a general formula of [(PbCaSr){Ti(ZnW)}O], and x, y, and z satisfy 0&#x2266;x&#x2266;0.2 (preferably 0&#x2266;x&#x2266;0.15), 0&#x2266;y&#x2266;0.2 (preferably 0&#x2266;y&#x2266;0.1), 0.1&#x2266;x+y&#x2266;0.2, and 0.04&#x2266;z&#x2266;0.1. It is also preferable that the piezoelectric ceramic composition contains 0.05 weight part to 1.0 weight part of a Mn component calculated in terms of MnCOwith respect to 100 weight parts of the main component. A piezoelectric part includes a piezoelectric ceramic element that is formed by the piezoelectric ceramic composition. It is thereby possible to realize a piezoelectric ceramic composition that can be fired at low temperature, that has a high Curie point Tc resistant to a reflow heating treatment on a lead-free solder, and that exhibits satisfactory piezoelectricity, and a piezoelectric part using this piezoelectric ceramic composition.

Piezoelectric ceramic composition and piezoelectric part

A piezoelectric ceramic whose resonance frequency temperature characteristic can be easily adjusted is provided. It contains first and second parts (and) which can be alternately stacked layers. The first and second parts (and) are each composed of a compound having a bismuth layer structure, such as a complex oxide containing at least Sr, Bi, and Nb, and have degrees of c-axis orientation different from each other. Since the resonance frequency temperature characteristics change according to the degree of orientation, the first and second parts (and) having different degrees of orientation are appropriately combined so that the resonance frequency temperature characteristics of the piezoelectric ceramic () as a whole is easily adjusted.

Piezoelectric ceramic and method for making the same, and piezoelectric resonator and method for making the same

Anisotropically shaped ceramic particles are represented by the general formula {(KNaLi)(NbTa)O+aMeO} (where Me is at least one element selected from the group consisting of antimony, copper, manganese, vanadium, silicon, titanium, and tungsten; and b is a positive number determined by the valence of Me), where x, y, z, and a satisfy 0&#x2266;x&#x2266;0.5, 0&#x2266;y&#x2266;0.3, 0&#x2266;z&#x2266;0.3, and 0.001&#x2266;a&#x2266;0.1, respectively. The anisotropically shaped ceramic particles have a plate-like shape. The average particle size is 1 to 100 &#x3bc;m, and the ratio D/t of the maximum diameter D of a main surface to the thickness t in a direction perpendicular to the main surface is 2 or more, preferably 5 or more. Thus, anisotropically shaped ceramic particles suitable as a reactive template for preparing a crystal-oriented alkali metal niobate-based ceramic can be produced at relatively low production costs without the need for a complicated production process.

Anisotropically shaped ceramic particles and method for producing the same

A piezoelectric ceramic composition includes a bismuth layer compound containing at least Sr, Bi and Nb, e.g., (SrNd)BiNbO, as a main component and 2 parts by weight or less (excluding 0 part by weight), preferably 0.04 part by weight to 0.5 part by weight, of Cu in terms of CuO relative to 100 parts by weight of the main component. From the viewpoint of improvement in sinterability, 0.1 part by weight to 2 parts by weight of Mn in terms of MnCOrelative to 100 parts by weight of the main component is preferably contained. As a result, it is possible to obtain a piezoelectric ceramic composition resisting no deterioration in piezoelectricity even when a rapid temperature change occurs, and an advantageous piezoelectric component, such as a piezoelectric actuator or a piezoelectric resonator, manufactured using the piezoelectric ceramic composition.

Piezoelectric ceramic composition and piezoelectric component

A piezoelectric ceramic composition that is based on a layered bismuth compound composed of Sr, Bi, Nb, oxygen, contains an additional monovalent metallic element. The piezoelectric ceramic composition has an elevated Curie point, is highly reliable at higher temperatures, that is, minimizes the reduction in the piezoelectric effect, and is useful as a material for piezoelectric ceramic devices that contain little or no lead or lead compounds. The layered bismuth compound contains not more than about 0.125 mol and more than 0 mol of the monovalent metallic element for 1 mol of Nb.

Piezoelectric ceramic composition and piezoelectric ceramic device composed of same

A piezoelectric element contains a piezoelectric ceramic body having a layered perovskite structure, and has the C axis selected and oriented in the thickness direction. In the piezoelectric ceramic body, line shaped electrodes are formed perpendicular to the C axis selected and oriented. The electrodes exposed at both of the end faces of the piezoelectric ceramic body are covered with conductive materials and insulation materials. The piezoelectric ceramic body is polarized in the opposite directions on both of the sides of electrodes arranged in the width direction. Moreover, external electrodes are formed on the faces where the conductive materials and the insulation materials are formed, whereby two groups of the electrodes are arranged in an interdigital electrode form.

Method of producing a piezoelectric element

A laminate type piezoelectric element having an improved piezoelectric property is provided. Vibration electrodes are arranged in a piezoelectric body, and high-order vibration of the thickness vibration is excited. The piezoelectric ceramic includes two ceramic piezoelectric layers which are laminated, and are integrally formed. Each of the ceramic piezoelectric layers contains ceramic crystal grains having shape anisotropy and spontaneous polarization preferentially oriented in one plane. The in-plane direction of this plane is perpendicular to the principal surfaces of the ceramic piezoelectric layers. The ceramic piezoelectric layers are polarized in the same thickness direction.

Piezoelectric element and method for manufacturing the same

A ceramic powder of grains having a shape-anisotropy is mixed with a calcined or uncalcined (or both) powder of a ceramic raw material. A ceramic slurry containing the produced mixed powder, a solvent and a binder is prepared and the ceramic slurry is formed into a sheet. A laminate comprised of a plurality of the sheets laminated to each other is uniaxially pressed to form an oriented product in such a manner that the length of the laminate in the direction parallel to the pressing axis becomes larger than that before the pressing, and the area of a plane perpendicular to the pressing axis of the laminate becomes larger than that before the pressing. The oriented formed product is fired and sintered.

Method of producing ceramic

In a piezoelectric ceramic containing a bismuth layer compound containing Ca, Bi, Ti, and O, as a main component, the molar ratio of Ca to Bi to Ti in the bismuth layer compound, which is the main component, is represented by a:b:c and formulas 0.15&lE;a/c<0.25 and 3.5&lE;(2a&plus;3b)/c&lE;3.88 are satisfied.

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Kusatsu, Japan

Masahiko Kimura