Tohoku University

Tohoku Techno Arch Co., Ltd.

Furukawa Co., Ltd.

Piezo Studio Inc.

Ca, Inc.

The University of Tokyo

Stella Chemifa Corporation

Kei Kamada

Akira Yoshikawa

Yuui Yokota

Yuji Ohashi

Shunsuke Kurosawa

Yasuhiro Shoji

Kenji Inoue

Tsuguo Fukuda

Kenji Aoki

Hiroyuki Takahashi

Hiroki Sato

Takayuki Yanagida

Yui Yokota

Tomohiko Satonaga

Yu Igarashi

Mototaka Arakawa

Hiraku Ogino

Kosuke Tsutsumi

Masatoshi Ito

Takanori Endo

Shigeki Ito

Hiroyuki Amano

Yoshiyuki Usuki

Takahiko Horiai

Akihiro Yamaji

Tetsuo Kudo

Rikito Murakami

Akira; Yoshikawa

Tomohiko; Satonaga

Kenji; Aoki

Takayuki Nihei

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

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

The present invention provides an oxide-base scintillator single crystal having an extremely large energy of light emission, adoptable to X-ray CT and radioactive ray transmission inspection apparatus, and more specifically to provide a Pr-containing, garnet-type oxide single crystal, a Pr-containing perovskite-type oxide single crystal, and a Pr-containing silicate oxide single crystal allowing detection therefrom light emission supposedly ascribable to 5d-4f transition of Pr.

Pr-containing scintillator single crystal, method of manufacturing the same, radiation detector, and inspection apparatus

The garnet-type crystal for a scintillator of the present invention is represented by General Formula (1), (2), or (3),GdCeREAlGaO&#x2003;&#x2003;(1)wherein in Formula (1), 0.0001&#x2266;x&#x2266;0.15, 0&#x2266;y&#x2266;0.1, 2&#x3c;z&#x2266;4.5, and RE represents at least one selected from Y, Yb, and Lu;GdCeLuAlGaO&#x2003;&#x2003;(2)wherein in Formula (2), 0.0001&#x2266;a&#x2266;0.15, 0.1&#x3c;b&#x2266;3, and 2&#x3c;c&#x2266;4.5;GdCeRE'AlGaO&#x2003;&#x2003;(3)wherein in Formula (3), 0.0001&#x2266;p&#x2266;0.15, 0.1&#x3c;q&#x2266;3, 1&#x3c;r&#x2266;4.5, and RE&#x2032; represents Y or Yb.

Garnet-type crystal for scintillator and radiation detector using the same

An electric signal produced by a photo-electric conversion element () is input to a comparator (). The comparator () judges whether the electric signal output from the amplifier () exceeds a reference voltage or not, and outputs a HIGH signal if 'exceeds'. A reference voltage modifier unit () elevates the reference voltage, after a predetermined time period elapses since the comparator () judged that the electric signal reached or exceeded the reference voltage. The signal processor calculates an incidence time which represents a time when the signal light starts to enter the photo-electric converter unit (), by correcting a rise-up time of the electric signal when it reaches or exceeds the reference voltage, based on a pulse width which represents a time period from when the electric signal exceeds the reference voltage, up to when the electric signal falls below the reference voltage.

Signal light detection device and method of detecting signal light

A rare earth fluoride solid solution material (polycrystal and/or single crystal) characterized in that the material is obtained by mutually combining a plurality of rare earth fluorides having phase transitions and having different ion radii, respectively, so that the rare earth fluoride solid solution material is free of phase transitions. A rare earth fluoride solid solution material (polycrystal and/or single crystal) characterized in that the material is represented by (RERE')F(0.0000&#x3c;y&#x3c;1.0000), wherein RE represents one or two or more selected from Sm, Eu, and Gd, and RE&#x2032; represents one or two or more selected from Er, Tm, Yb, Lu, and Y. A rare earth fluoride solid solution material (polycrystal and/or single crystal) represented by MRERE&#x2032;F., wherein RE is one or two or more selected from Ce, Pr, Nd, Eu, Tb, Ho, Er, Tm, or Yb, RE&#x2032; is one or two or more selected from La, Sm, Gd, Dy, Lu, Y, and Sc, and M is one or more of Mg, Ca, Sr, and Ba.

Solid solution material of rare earth element fluoride (polycrystal and single crystal), and method for preparation thereof, and radiation detector and test device

Growing community of inventors

Miyagi, Japan

Kei Kamada