Tohoku University

Piezo Studio Inc.

Ca, Inc.

Tdk Corporation

Tanaka Kikinzoku Kogyo K.k.

Tohoku Techno Arch Co., Ltd.

Yuui Yokota

Akira Yoshikawa

Kei Kamada

Shunsuke Kurosawa

Yuji Ohashi

Yasuhiro Shoji

Kenji Inoue

Akira Suzuki

Koichi Sakairi

Kunihiro Tanaka

Masato Sato

Ko Onodera

Kazushige Tohta

Tatsuya Nakazawa

Yu Igarashi

Muneki Nakamura

Mototaka Arakawa

Masatoshi Ito

Toetsu Shishido

Rikito Murakami

Takahiko Horiai

Hiroyuki Amano

Akihiro Yamaji

Tetsuo Kudo

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

To provide a vibrator made of a piezoelectric crystal having a larger electromechanical coupling coefficient and a more satisfactory frequency-temperature characteristic than those of quartz, a vibrating piece () is made of a CaTa(GaAl)SiOsingle crystal (0&#x3c;x&#x2264;1). In the single crystal, letting &#x3b8; be a rotation angle from an X-Z plane about an X-axis serving as a rotation axis, 18x+17.5&#x2264;&#x3b8;&#x2264;24x+24.5 is set. In addition, the vibrating piece () is made of a CaNb(GaAl)SiOsingle crystal (0&#x3c;x&#x2264;1). In the single crystal of this arrangement, letting &#x3b8; be a rotation angle from an X-Z plane about an X-axis serving as a rotation axis, 25x+23.083&#x2264;&#x3b8;&#x2264;32x+26.167 is set.

Piezoelectric vibrator and sensor

To improve the Q value of a piezoelectric thin-film element in a state in which unnecessary vibration is suppressed, an acoustic reflection film () is affixed to a first electrode (), a piezoelectric single-crystal substrate () is thinned by polishing from the other surface () of the piezoelectric single-crystal substrate (), such that the first electrode () and piezoelectric thin film () are piled on the piezoelectric single-crystal substrate (). In this polishing, a pressure (polishing pressure) to the surface () during polishing in an electrode formation region where the first electrode () is formed differs from that in a non-electrode formation region around the electrode formation region. Consequently, the electrode formation region of the piezoelectric thin film (), where the first electrode () is formed, is made thinner than the non-electrode formation region around the electrode formation region.

Method for manufacturing piezoelectric thin-film element

An illuminant has a short fluorescence lifetime, high transparency, and high light yield and a radiation detector uses the illuminant. The illuminant is appropriate for a radiation detector for detecting gamma-rays, X-rays, &#x3b1;-rays, and neutron rays, and has high radiation resistance, a short fluorescence decay time and high emission intensity. The illuminant has a garnet structure using emission from the 4f5d level of Ce, and includes a garnet illuminant prepared by co-doping of at least one type of monovalent or divalent cation at a molar ratio of 7000 ppm or less with respect to all cations, to an illuminant having a garnet structure represented by general formula CeREMO(where 0.0001&#x2264;x&#x2264;0.3, 0&#x2264;y&#x2264;0.5 or 0&#x2264;y&#x2264;&#x2212;0.5, M is one type or two or more types selected from Al, Lu, Ga, and Sc, and RE is one type or two or more types selected from La, Pr, Gd, Tb, Yb, Y, and Lu).

Illuminant and radiation detector

The present invention provides a metal wire rod composed of iridium or an iridium alloy, wherein the number of crystal grains on any cross-section in a longitudinal direction is 2 to 20 per 0.25 mm, and the Vickers hardness at any part is 200 Hv or more and less than 400 Hv. The iridium wire rod is a material which is produced by a &#x3bc;-PD method, and has low residual stress and which has a small change in the number of crystal grains and hardness even when heated to a temperature equal to or higher than a recrystallization temperature (1200&#xb0; C. to 1500&#xb0; C.). The metal wire rod of the present invention is excellent in oxidative consumption resistance under a high-temperature atmosphere, and mechanical properties.

Metal wire rod composed of iridium or iridium alloy

A crystal material that is represented by a general formula (1): (REABM')(Si,M&#x2033;)O(1), the crystal material having a pyrochlore type structure, being a nonstoichiometric composition, and being a congruent melting composition, wherein in Formula (1), A contains at least one or more selected from Gd, Y, La, Sc, Yb, and Lu; B contains at least one or more selected from La, Gd, Yb, Lu, Y, and Sc; 0.1&#x2264;y&#x3c;0.4; RE contains at least one or more selected from Ce, Pr, Nd, Eu, Tb, and Yb; 0&#x3c;x&#x3c;0.1; M&#x2032; and M&#x2033; contain at least one or more selected from Li, Na, K, Mg, Ca, Sr, Ba, Ti, Zr, Hf, Fe, Ta, and W; 0&#x2264;s&#x3c;0.01 and 0&#x2264;t&#x3c;0.01; and 0&#x3c;|&#x3b1;|&#x3c;0.3 and 0&#x2264;|&#x3b2;|&#x3c;0.3 and 0&#x2264;|&#x3b3;|&#x3c;0.5.

Crystal material, method for manufacturing crystal, radiation detector, nondestructive inspection apparatus, and imaging apparatus

A crystal material represented by a general formula (1):(GdLaMERE)MMO&#x2003;&#x2003; (1),where ME is at least one selected from Y, Yb, Sc, and Lu; RE is Ce or Pr; MM is at least one selected from Si and Ge; and ranges of x, y, and z are represented by the following (i): (i) 0.0&#x2266;x+y+z&#x3c;1.0, 0.05&#x2266;x+z&#x3c;1.0, 0.0&#x2266;y&#x3c;1.0, and 0.0001&#x2266;z&#x3c;0.05 (where, when RE is Ce, y=0 is an exception).

Crystal material, radiation detector, imaging apparatus, nondestructive inspection apparatus, and lighting apparatus

An oxide material having a langasite-type structure having a desired surface condition and a desired outer shape is obtained stably. By adding at least one selected from the group consisting of Ir, Pt, Au, and Rh to a raw material which is a composition used for producing a desired oxide material as an additive element, it is possible to control the wettability between a die portion at a bottom end of a crucible and a melt of the raw material, thereby implementing stable production of the oxide material while controlling the wetting and spread of the melt of the raw material leaked out through a hole of the crucible.

Langasite-type oxide material, method for producing same, and raw material used in the production method

Growing community of inventors

Sendai, Japan

Yuui Yokota