著者

堀越 正美

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.38, no.4, pp.296-299, 1996-08-30 (Released:2010-09-30)

著者

藤井 保彦

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.54, no.3, pp.131-138, 2012-06-30 (Released:2012-07-03)

参考文献数

49

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In this article, I have reviewed a series of research on a various phase transitions such as (1) structural phase transitions of perovskite compounds driven by soft phonons, (2) pressure-induced molecular dissociation and metallization observed in solid halogens, and (3) the “Devil's Flower” type phase diagram observed in two compounds with frustrating interactions. Also commented is on the so-called “Small Science at Large Facility” typically symbolized by neutron and synchrotron radiation experiments like the present research.

著者

松井 良夫

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.39, no.2, pp.157-167, 1997-04-28 (Released:2010-09-30)

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This article is the first introduction to transmission electron microscopy (TEM) for beginners interested in the crystal structure analysis by means of electron diffraction and highresolution electron microscopy. Brief history of TEM, basic arrangements of TEM instruments, how to obtain selected area electron diffraction patterns, and how to prepare specimen by “crushing method”, are described.

著者

可知 祐次

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.16, no.1, pp.115-119, 1974-02-20 (Released:2010-09-30)

参考文献数

17

被引用文献数

1

著者

石井 真史 上杉 文彦 小澤 哲也

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.62, no.1, pp.35-42, 2020-02-29 (Released:2020-03-06)

参考文献数

16

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Along with the advancement of measurement technologies, a large amount of experimental crystallographic data can be obtained easily, so that objective and rapid analysis suitable for batch process is strongly required. This article introduces recent research on objective and rapid analysis of crystal structure using X-rays or electron beams. For one-dimensional X-ray diffraction pattern, non-negative linear regression (NNLS) using diffraction patterns provided by public database has achieved more objective and faster analysis than conventional manual works. With regard to two-dimensional electron and X-ray diffraction, good objective and rapid analysis was realized for several types of materials by using artificial intelligence (AI) based on convolutional neural network. On the other hand, the sparsity inherent in the diffraction pattern was found to cause a lack of information, and universal applicability of material property prediction using AI that depends on training data is still open to question. However, the fact that AI itself has the potential ability to solve complex images, a breakthrough technology for universal two-dimensional objective and rapid analysis might be found in progressing research.

著者

有馬 孝尚

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.53, no.5, pp.317-325, 2011-10-31 (Released:2011-11-20)

参考文献数

34

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The interplay between magnetism and electricity in matter has become a central issue of condensed-matter physics. Here I focus on the ferroelectricity induced by magnetic order mostly in frustrated magnets, which is nowadays referred to as magneto-electric (ME) multiferroic. Some distinct types of microscopic origins relevant to the spin-driven ferroelectricity are discussed. It is also shown that the frustration based spin-driven ferroelectrics can exhibit nonlinear and giant ME responses of phase transition type.

著者

金子 耕士

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.61, no.4, pp.237-242, 2019-12-15 (Released:2019-12-15)

参考文献数

24

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Neutron and X-ray are complementary probes for structural study. Whereas X-ray is superior in terms of brilliance and resolution in general, neutron diffraction has better spatial resolution reflecting the difference in scattering medium; electron and nuclei for X-ray and neutron, respectively. This difference results in the fact that neutron diffraction has higher sensitivity to probe thermal vibration and off-center potential in a crystal. Here, as an example, I will show single crystal neutron diffraction study on ‘rattling’ in rare-earth based filled skutterudite compounds.

著者

池田 拓史

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.61, no.4, pp.215-223, 2019-12-15 (Released:2019-12-15)

参考文献数

41

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Zeolites having various properties such as molecular adsorption, molecular sieves and solid-acids are widely used industrially as one of the major inorganic nanoporous materials. Powder X-ray diffraction is the most powerful structural analysis method because most porous materials can only be synthesized as polycrystalline powder. This article briefly describes some of our structural studies on novel zeolites, layered silicates, organic-inorganic hybrid porous materials determined by ab-initio structure analysis using powder X-ray diffraction data. In addition, improvement of the function of Rietveld analysis software was indispensable for the determination of these complex crystal structures. In the past development of multipurpose program RIETAN, we have incorporated many functions such as split-type profile functions, composite background function, MEM-based pattern fitting, and Le Bail method. This enables the highest level of pattern fitting for all angular dispersion powder diffraction patterns and enables efficient ab-initio structure analysis.

著者

大場 茂

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.57, no.3, pp.147-154, 2015-06-30 (Released:2015-07-01)

参考文献数

11

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The second lesson in this tutorial course of SHELXL includes restraints and constraints of the geometrical as well as the atom displacement parameters, and the strategy of the modeling and refinement of the disordered structures. Treatment of a troublesome disorder of pentane around the special position will be illustrated. The effect of randomly distributed solvents may be corrected either by a bulk solvent approximation or by using PLATON/SQUEEZE as a filter. Some examples of disordered inorganic structures are shown, where the atom occupation factors have been restrained to maintain the electric neutrality of the crystals.

著者

大嶋 建一

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.57, no.4, pp.250-251, 2015-08-31 (Released:2015-09-01)

著者

佐藤 眞直

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.56, no.4, pp.259-262, 2014-08-31 (Released:2014-09-03)

参考文献数

6

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X-ray diffraction technique is suitable for in-situ observation and quantitative analysis of phenomena occurring in manufacturing process of industries. Its time resolution has been progressed by applying synchrotron radiation. Two cases of industrial application of synchrotron radiation are introduced.

著者

雨宮 慶幸

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.61, no.2, pp.136-137, 2019-05-31 (Released:2019-06-05)

著者

坂本 昌巳 三野 孝 藤田 力

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.47, no.2, pp.135-139, 2005-04-27 (Released:2010-09-30)

参考文献数

20

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Synthesis of optical active compounds from achiral or racemic materials is one of the most impressive studies in organic chemistry. Here we provide two new technique of generation of optical activity without anyl outside chiral source. One is the breaking of chiral symmetry of axially chiral materials via racemization-preferential crystallization method. Another involves the asymmetric reaction using the frozen chirality generated by chiral crystallization of achiral materials.

著者

加藤 昌子

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.57, no.2, pp.110-115, 2015-04-30 (Released:2015-04-30)

参考文献数

26

被引用文献数

1

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Recent developments of luminescent copper(I) complexes are remarkable and some copper(I) complexes exhibit interesting chromic behaviors of luminescence in response to outer stimuli such as temperature, vapor, and mechanical force. In this article, recent progress of luminescent chromic copper(I) complexes is introduced. Tetranuclear copper(I) clusters with the cubanetype [Cu4I4] core present good examples of luminescence thermochromism, vapochromism, and mechanochromism. In addition, some unique chromic systems are found recently: A dinuclear copper(I) complex, [Cu2(μ-I)2(dmso)2(PPh3)2](dmso = dimethyl sulfoxide) exhibits unique photochromic luminescence on the basis of the flip and release of dmso. Highly luminescent mononuclear copper(I) complexes with ternary ligand systems, [CuI(PPh3)2(L)](L = N-heteroaromatic compounds) are generated by the mechanical grinding.

著者

前田 将司

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.52, no.1, pp.25-30, 2010-02-28 (Released:2011-02-25)

参考文献数

27

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Here we describe the long awaited atomic structure of the gap junction channel. The structure reveals intra-/inter- monomer interactions, which stabilize the channel structure, and intercellular interactions between two apposing hemichannels. The structure also reveals the pore structure in detail, charge distribution, pore-lining residues and so on. The novel structure, pore funnel, is found on the top of the pore and the relationship with channel gating could be inspected.

著者

相澤 俊 安藤 寿浩

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.38, no.2, pp.160-166, 1996-04-30 (Released:2010-09-30)

参考文献数

16

被引用文献数

1

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Surface vibration of CVD-grown diamond surface is measured by HR-EELS. Hydrogen is adsorbed on the sp3-hybridized carbon. On the (001) 2×1 surface, one C-H stretching vibration appears consistently with the dieter-chain model. On the (111) 1×1 surface, two C-H stretching modes appear, which suggests methyl termination model. But the phonon dispersion in the low energy region is well explained by the monohydride termination model. Uniformity of the surface should be checked to discuss this inconsistency. Hydrogen exchange with the gas-phase and the hydrogen desorption/adsorption processes are also investigated.

著者

阿部 洋 大嶋 建一

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.38, no.2, pp.151-159, 1996-04-30 (Released:2010-09-30)

参考文献数

48

被引用文献数

1

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A characteristic waiting time appears at fixed temperature above Tc or Ms for elements, alloys and polymers, where Tc is the usual first-order phase transition temperature and Ms is the normal martenstic phase transition temperature. This waiting time is called incubation time and related with the nucleation probability derived from a nucleation barrier. That is why nucleation process is regarded as thermal activated process at the non-equilibrium state. In particular, such a long incubation time of In-Tl alloys has a good agreement with experimental results by using Roitburd method. Furthermore, detailed and accurate experiments enable us to be aware that two dimensional growth occurs above Tp, where peculiar temperature, Tp, controls the time development of diffraction patterns and appears above Ms in this system.In contrast to soft phonon model, incubation time is essential property of the first-order phase transition and the key to resolve nucleation and growth process.

著者

竹中 章郎

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.48, no.5, pp.311-319, 2006-10-31 (Released:2010-09-30)

参考文献数

4

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As an easy technique for phase determination in X-ray analysis of macromolecular crystals, the molecular replacement method is widely used. Available computer programs are highly sophisticated to user friendly so that users can use them without knowledge on the theoretical backgrounds. To develop the technique to more powerful tool, as well as to resolve individual problems in special cases, it is essential to understand the details of the backgrounds. Here the theories of the method with the historical backgrounds, its availability and capability, practical usage and trouble shooting will be described.

著者

渡辺 伝次郎 三俣 千春 高橋 研 田中 寿郎

出版者

日本結晶学会

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.31, no.Supplement, pp.OB-5, 1989-11-27 (Released:2010-09-30)

著者

金原 数 西郷 和彦

出版者

The Crystallographic Society of Japan

雑誌

日本結晶学会誌 (ISSN:03694585)

巻号頁・発行日

vol.38, no.6, pp.414-420, 1996-12-30 (Released:2010-09-30)

参考文献数

14

被引用文献数

1 1

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X-ray crystallographic studies were carried out for conglomerate salts, racemic-compound salts, and enantiomerically pure salts of chiral primary amines with achiral mono-carboxylic acids. The crystal structures of the conglomerate salts revealed that these crystals can be regarded as being a supramolecular assembly of a characteristic columnar hydrogen-bond network, in which the ammonium cations and the carboxylate anions are aligned around a twofold screw axis (21-column) . On the other hand, the crystal structures of the racemic-compound salts could be roughly classified into two types. One type is a crystal consisting of 21columns; the other type is a crystal consisting of a different type of columnar hydrogen-bond network, in which the ammonium cations and the carboxylate anions are related by inversion centers (i-column) .These results suggest that both the formation and the assembly of 21columns are essential in the formation of conglomerates for these salts.