Tohoku University

Other

Piezo Studio Inc.

Chuo Precision Industrial Co., Ltd.

Mototaka Arakawa

Yuji Ohashi

Jun-ichi Kushibiki

Akira Yoshikawa

Kei Kamada

Yuui Yokota

Shunsuke Kurosawa

Yasuhiro Shoji

Yu Igarashi

Kenji Inoue

Yukihiro Shinozaki

Akihiro Yamaji

Ryoichi Okabe

Tetsuo Kudo

Jun-Ichi Kushibiki

Yukihiro Chuo Precision Ind Co Ltd Shinozaki

The present invention makes clear and defines a congruent composition of a langasite-based oxide, and establishes a method of manufacturing a crystal by any desired composition of AEME(GaAl)SiO(AE is an alkaline-earth metal, ME is Nb or Ta, 0&#x2264;x&#x2264;1, &#x2212;0.5&#x3c;a&#x2264;0 or 0&#x3c;a&#x3c;0.5, &#x2212;0.5&#x3c;b&#x2264;0 or 0&#x3c;b&#x2264;0.5, and &#x2212;0.5&#x3c;c&#x2264;0 or 0&#x3c;c&#x3c;0.5, excluding a=b=c=0). This makes it possible to suppress the formation of an impurity, and improve the yield and crystal manufacturing rate. The raw material is a raw material mixture prepared by mixing an alkaline-earth metal or its carbonate or oxide, Nb or Ta or its oxide, Ga or its oxide, Al or its oxide, and Si or its oxide.

Crystal material and method of manufacturing the same

By measuring, for an ultra-low-expansion glass material, the frequency dependence of acoustic velocities and attenuation coefficients of bulk waves (longitudinal waves and shear waves), and the density, its fundamental acoustic properties are revealed, and a standard specimen for use in system calibration is prepared. By an absolute calibration method using the standard specimen, absolute values for both the LSAW and LSSCW velocities are obtained. Moreover, there are obtained relationships for the acoustic properties and the coefficient of thermal expansion to evaluate the coefficient of thermal expansion from the acoustic properties. In case there is a distribution of characteristics due to periodic striae, an accurate acoustic property distribution in the substrate can be ascertained and an evaluation performed, by selecting for the substrate a cutting angle with respect to the striae plane.

Evaluation method for coefficient of thermal expansion of ultra-low-expansion glass material

A measuring system including a linear gauge is placed on a vibration isolation table , and this system assembly is placed in a temperature controllable, constant-temperature chamber. A specimen table , which has a centrally-disposed circular protrusion C of a diameter sufficiently smaller than a specimen under measurement, is mounted on a surface plate of a linear gauge . The position of a measuring element is measured when it is brought into contact with the centrally-disposed circular protrusion C, and the position of the measuring element is measured when it is brought into contact with the specimen placed on the specimen table. The measured values are used to determine the thickness of the specimen.

Thickness measuring apparatus and method

Growing community of inventors

Miyagi, Japan

Mototaka Arakawa