論文 - 井田 隆
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Hisayoshi Nakamura, Satoru Yamazaki, Tomohiko Ohnishi, Takashi Ida, Hideo Toraya
Powder Diffraction 16 ( 2 ) 65 - 70 2001年06月
記述言語：英語 掲載種別：研究論文（学術雑誌）
The Monte Carlo method is applied to finding missing atoms in solving inorganic crystal structures without applying a rigid-body approximation. Whole powder patterns of alpha-SiO2 and Mg2SiO4 were used for testing a procedure. Four atoms among the six in the asymmetric unit of Mg2SiO4 could be found in the present analysis. The use of well-refined profile parameters enhanced the frequency of correct structure configurations in the Monte Carlo search. Utilizing structural information available for constructing a trial configuration is also considered to be important for efficiently searching the structure solution. A procedure for assignment of equivalent positions to respective atoms is presented. The method can be used as a powerful tool for finding missing atoms in a partially solved structure. A histogram of weighted reliability index in Monte Carlo calculations is very informative for evaluating the performance of the method.
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粉末Ｘ線回折プロファイル関数の開発 招待あり 査読あり
井田隆
日本結晶学会誌 43 ( 3 ) 269 - 274 2001年06月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌）
A model peak profile function synthesized by multiple convolutions of the intrinsic peak profile with the instrumental functions of a conventional powder X-ray diffractometer has been developed. The general recipe for deriving accurate instrumental functions as well as an efficient numerical method for evaluating the convolutions are presented. The validity of the model function has been examined by comparing the experimental peak profiles measured in different conditions. The use of the convoluted model profile function provides a convenient and reliable way to estimate the integrated intensities, intrinsic peak positions and broadenings.
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装置関数との畳み込みによる粉末回折ピークのモデルプロファイル関数
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理学電機ジャーナル 32 ( 1 ) 24 - 33 2001年04月
掲載種別：研究論文（その他学術会議資料等）
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Model peak profile functions for powder diffractometry as convolutions with instrumental functions
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Rigaku J. 18 ( 2 ) 47 - 56 2001年04月
掲載種別：研究論文（学術雑誌）
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Peak profile function for synchrotron X-ray diffractometry（共著） 査読あり
T. Ida, H. Hibino, H. Toraya
Journal of Applied Crystallography 34 ( 2 ) 144 - 151 2001年04月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
A formula of the instrumental function for a high-resolution synchrotron X-ray diffractometer, equipped with a flat crystal analyser and a set of Soller slits for limiting the axial divergence of the diffracted beam, has been derived. The formula incorporates the effects of (i) the axial divergence of the diffracted beam limited by the Soller slits, (ii) the Bragg angle of the flat crystal analyser, and (iii) the tilt angle defined as the deviation of the normal direction of the analyser face from the goniometer plane. The model profile function given by the convolution of a Lorentzian function with the instrumental function has been applied to fit the experimental diffraction peak profiles of standard Si powder (NIST SRM640b) measured with a high-resolution synchrotron X-ray diffractometer, MDS, on beamline BL4B2 at the Photon Factory in Tsukuba. The convolution has been calculated by applying an efficient algorithm for numerical integration. The profile function reproduces not only the experimental profiles measured with a well aligned crystal analyser, but also significantly distorted profiles arising from misalignment of the analyser, with Rp values within 1.4%, by varying only the instrumental parameter for the tilt angle. It is suggested that further convolution with a Gaussian distribution is practically not necessary for the model instrumental function to fit the data collected with MDS. More rapid computation can be achieved by applying an analytical formula of the profile function, when the tilt angle of the crystal analyser is within about 0.2°.
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Ab initio structure determination of monoclinic 2,2-dihydroxymethylbutanoic acid from synchrotron radiation powder diffraction data: combined use of direct methods and the Monte Carlo method（共著） 査読あり
Y. Tanahashi, H. Nakamura, S. Yamazaki, Y. Kojima, H. Saito, T. Ida, H. Toraya
Acta Crystallographica Section B 57 ( 2 ) 184 - 189 2001年04月
記述言語：英語 掲載種別：研究論文（学術雑誌）
The crystal structure of 2,2-dihydroxymethylbutanoic acid (C6H12O4) in monoclinic form has been determined ab initio from synchrotron radiation powder diffraction data. Two O and five C atoms were first derived by direct methods. Two missing O atoms and one C atom were found by the Monte Carlo method without applying constraint to their relative positions. Positional and isotropic displacement parameters of these non-H atoms were refined by the Rietveld method. Molecules are linked by hydrogen bonds and they make sheet-like networks running parallel to the (010) plane. The Monte Carlo method is demonstrated to be a powerful tool for finding missing atoms in partially solved structure.
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Extended pseudo-Voigt function for approximating the Voigt profile（共著） 査読あり
T. Ida, M. Ando, H. Toraya
Journal of Applied Crystallography 33 ( 6 ) 1311 - 1316 2000年12月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
The formula of the pseudo-Voigt function is extended in order to improve the accuracy when approximating the Voigt profile. When the extended formula is applied for curve fitting to a Voigt profile, the accuracy of the estimated profile parameters can be improved considerably.
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基礎パラメータ法による粉末回折ピークのプロファイルフィッティング
井田隆
名古屋工業大学セラミックス研究施設年報 9 ( 2 ) 1 - 7 2000年04月
記述言語：日本語 掲載種別：研究論文（大学，研究機関等紀要）
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Effect of Sample Transparency in Powder Diffractometry with Bragg-Brentano Geometry as a Convolution 査読あり
T. Ida, K. Kimura
Journal of Applied Crystallography 32 ( 5 ) 982 - 991 1999年10月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
Mathematical formulae for the effect of sample transparency in powder diffractometry with Bragg-Brentano geometry are examined. The overall profile function given by triple convolution of the pseudo-Voigt function with the horizontal divergence, sample transparency and vertical divergence aberration functions reproduces the experimental peak profiles well.
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Flat-Specimen Effect as a Convolution in Powder Diffractometrywith Bragg-Brentano Geometry（共著） 査読あり
T. Ida, K. Kimura
Journal of Applied Crystallography 32 ( 4 ) 634 - 640 1999年08月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
The flat-specimen effect on the peak profile in powder diffractometry with Bragg-Brentano geometry can quantitatively be treated as a convolution with an asymmetric window function. The formula of the window function and a practical method for numerical calculation of the convolution are proposed. By applying the model function given by the convolution of the pseudo-Voigt function with asymmetric window functions based on vertical (axial) divergence and the flat-specimen effect, experimental profiles measured with a conventional diffractometer are fairly well reproduced with only a few parameters. When this function is applied to the analysis of experimental diffraction profiles of a lanthanum hexaboride (LaB6) standard sample measured with a conventional powder X-ray diffractometer, the lattice constant is estimated as a = 4.15685 (2)-4.15693 (2) Å at 299 (1) K, without the use of any other standard material or preceding correction of systematic instrumental errors, while the specified value is a = 4.15695 (6) Å.
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An efficient method for calculating asymmetric diffraction peak profiles 査読あり
Takashi Ida
Review of Scientific Instruments 69 ( 11 ) 3837 - 3839 1998年11月
記述言語：英語 掲載種別：研究論文（学術雑誌）
DOI： 10.1063/1.1149220
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Thiol-derivatized AgI Nanoparticles: Synthesis,Characterization and Optical Properties（共著） 査読あり
Sihai Chen, Takashi Ida, Keisaku Kimura
J. Phys. Chem. B 102 ( 32 ) 6169 - 6176 1998年08月
記述言語：英語 掲載種別：研究論文（学術雑誌）
DOI： 10.1021/jp9809991
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Formula for the asymmetric diffraction peak profiles based on double Soller slit geometry 査読あり
Takashi Ida
Review of Scientific Instruments 69 ( 6 ) 2268 - 2272 1998年06月
記述言語：英語 掲載種別：研究論文（学術雑誌）
DOI： 10.1063/1.1148930
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Ionic conductivity of small-grain polycrystals of silver iodide（共著） 査読あり
T. Ida, K. Kimura
Solid State Ionics 107 ( 3-4 ) 313 - 318 1998年04月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
Small particles of AgI with various average size (140–680 nm) have been prepared by a gas-evaporation method. The powder X-ray diffraction patterns show that they are mixture of γ- and β-phases, and the mass fraction of the latter is roughly estimated at 20–25%. The room temperature conductivity of a polycrystalline pellet of small AgI particles shows enhancement by decreasing particle size, and the conductivity of 1.4×10−4 Ω−1 cm−1 has been observed in 140 nm-grain AgI polycrystal. The overall activation energy for conduction varies from 0.38 to 0.28 eV, depending on the average size of the particles.
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A novel method for large-scale synthesis of AgI nanoparticle（共著） 査読あり
Sihai Chen, Takashi Ida, Keisaku Kimura
Chemical Communications 1997 ( 23 ) 2301 - 2302 1997年12月
記述言語：英語 掲載種別：研究論文（学術雑誌）
Thiol-derivatised I–VII nanoparticles of AgI (7–16 nm) are prepared in large quantities by the reaction of silver nitrate with potassium iodide containing 1-thioglycerol in aqueous solution.
DOI： 10.1039/a705420c
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Colloidal stability of gold nanoparticles in 2-propanol under laser irradiation（共著） 査読あり
Y. Takeuchi, T. Ida, K. Kimura
The Journal of Physical Chemistry 101 ( 8 ) 1322 - 1327 1997年02月
記述言語：英語 掲載種別：研究論文（学術雑誌）
The influence of laser light irradiation at the surface plasmon frequency of the gold nanoparticles suspended in 2-propanol is examined by the UV−vis absorption spectral measurement and also by a transmission electron microscope. It has been found that the laser light irradiation on the colloidal suspension causes coagulation or dispersion of the particles depending on the particle concentration of the suspension. To investigate the cause of this finding, we have measured the ζ-potential of the particles by an electrophoretic light scattering method. This measurement suggests that the dispersion phenomenon of flocculates is due to the increment in the ζ-potential of the particles which prevents mutual access of negatively charged particles. The photochemical reaction, in which the gold particles obtain electrons from a solvent molecule, is suggested to be responsible for this process.
DOI： 10.1021/jp963107a
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Blue-green photoluminescence from ultrafine colloidal Si particles in 2-propanol（共著） 査読あり
Shingo Iwasaki, Takashi Ida, Keisaku Kimura
Japanese Journal of Applied Physics 35 L551 - L554 1996年05月
記述言語：英語 掲載種別：研究論文（学術雑誌）
We have prepared Si nanocolloids by trapping Si ultrafine particles (UFPs) prepared by gas evaporation into an organic solvent. The average diameter of the Si UFPs is 4.8 nm. Strong blue-green photoluminescence (PL) from the Si UFPs has been observed at room temperature. The peak energy of the broad PL band is about 2.5 eV. We have investigated the dependence of the PL intensity on the aging of the sample and the average diameter of the Si particles.
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Electrocrystallization, crystal structure, and solid state properties of halogen-bridged one-dimensional compound, {[Ni(en)<sub>2</sub>Br](ClO<sub>4</sub>)<sub>2</sub>}<sub>∞</sub>, having an elongated Ni...Ni distance（共著） 査読あり
Yoshiki Ozawa, Takayuki Ikuno, Shin-Ichi Amano, Takashi Ida, Akito Ibaraki, Keisaku Kimura, Koshiro Toriumi
Molecular Crystals and Liquid Crystals 278 189 - 197 1996年03月
記述言語：英語 掲載種別：研究論文（学術雑誌）
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Temperature effect on gold nanodispersion in organic liquids（共著） 査読あり
Y. TAKEUCHI, T. IDA, K. KIMURA
Surface Review and Letters 3 ( 1 ) 1205 - 1208 1996年02月
記述言語：英語 掲載種別：研究論文（学術雑誌）
The temperature effect on gold nanodispersion in organic liquids was examined by optical absorption spectroscopy and transmission electron microscopy. It was found that the color of the dispersion changed from purple just after preparation under a low-temperature condition to reddish purple or pink with the elevation of temperature up to room temperature. The optical properties of this system strongly coupled with the state of dispersions such as isolation, coagulation, and coalescence to sediment. Heating the dispersion above room temperature induced the instability of the colloidal system which also resulted in the color change of the dispersion.
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The preparation and properties of polycrystals of solid electrolyte ultrafine particles（共著） 査読あり
T. IDA, H. SAEKI, H. HAMADA, K. KIMURA
Surface Review and Letters 3 ( 1 ) 41 - 44 1996年02月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
We have investigated the transport properties of polycrystals of solid electrolytes, CuBr(I), CuCl(I), and AgI, by compressing submicron particles prepared by the evaporation method. The pellets of asgrown CuBr and CuCl particles tend to be contaminated by Cu(II), which may cause charge transport by hole conduction. After the CuCl particles are treated with acetone, the pellet shows significant ionic conduction. The pellet of purified particles 0.4-μm CuCl has a conductivity of 5×10−7Ω−1cm−1 at 25°C, and activation energy for conduction of 0.44 eV. The 0.7-μm AgI pellet also shows an enhanced conductivity of 5×10−5Ω−1cm−1 at 25°C, and activation energies of 0.04 eV between 60 and 5°C, and 0.23 eV below −25°C.
