巻号一覧
48 巻 (2021)
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48 巻, 1 号
選択された号の論文の6件中1～6を表示しています
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巻頭言
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古賀 信吉2021 年 48 巻 1 号 p. 1
発行日: 2021/01/25
公開日: 2022/06/20
ジャーナル フリーPDF形式でダウンロード (220K)
特集 － 物性研究における熱測定・熱分析 －
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高橋 仁徳, 芥川 智行, 中村 貴義2021 年 48 巻 1 号 p. 2-6
発行日: 2021/01/25
公開日: 2022/06/20
ジャーナル フリーMolecular machine is one of the important fields in supramolecular chemistry. We are developing supramolecular systems exhibiting mechanical motions in the crystalline state. Since the molecules are anisotropically and densely arranged in the crystalline phase, molecular motions in a crystal can be easily extracted as an external output. Supramolecules are highly designable. A variety of combinations of inorganic or organic cations with crown ethers will exhibit diverse physical responses derived from dynamic feature of supramolecular systems. We have been combining the supramolecular cations with the anionic metal-coordination complex of [Ni(dmit)2]– (dmit2– = 1,3-dithio-2-thione-4,5-dithiolate2–) showing peculiar magnetic and conducting properties due to the open-shell electronic structure. In this review, we introduce a series of multifunctional [Ni(dmit)2]– supramolecular crystals exhibiting interplay between supramolecular motion and electronic functions.抄録全体を表示PDF形式でダウンロード (1667K) -
高井 茂臣, 薮塚 武史, 八尾 健, 川路 均2021 年 48 巻 1 号 p. 7-11
発行日: 2021/01/25
公開日: 2022/06/20
ジャーナル フリーLa2Mo2O9-based system is one of the widely investigated oxide ion conductors for its excellent ionic conductivity at intermediate temperatures. The detailed phase relationships and transition phenomena also attract interests in combination with oxide ion conduction. In recent years, we found that low-temperature stable phase (β'–phase) with the quite similar structure with β–phase appears by annealing the supercooled β below 460 ºC for the sample x ~ 0.06 of La2-xBixMo2O9, and the transformation process from β into β' can be expressed based on Avrami’s equation. In addition, Ba- or Pb-substituted systems also exhibit the low-temperature β' phase through the annealing of supercooled β–phase. The electron diffraction and thermal hysteresis of conductivity suggested that subtle ordering of oxide ion is related to the formation of β'–phase. In this article, we show our recent research on the low-temperature phase transition phenomena on La2Mo2O9-based oxide ion conductors.抄録全体を表示PDF形式でダウンロード (1288K) -
中村 天彦, 渡辺 啓介2021 年 48 巻 1 号 p. 12-16
発行日: 2021/01/25
公開日: 2022/06/20
ジャーナル フリーThe phase behavior of the ionic liquid is supposed to depend on the thermal history. However, the details are not clear. The ionic liquid, 1-methyl-3-octylimidazolium tetrafluoroborate, abbreviated as [C8mim]BF4, has been known as a good glass-former, which can be cooled or heated at normal scanning rates without any phase transition. By heating from 183 K just below the glass transition temperature to 223 K, Tg + 33 K, a phase transition from the supercooled liquid to a liquid crystalline phase was observed by X-ray diffractometry. The assignment of the Bragg peaks indicates that a smectic A phase with a bilayer structure as seen in typical lamellar phases. The dielectric measurement was also performed on this material to investigate heating process depending on the thermal history. As the parameters of the thermal history, the initial temperature, Tini, for heating measurement and the equilibration time, teq, which means how long the sample is isothermally kept for recovery of the thermal homogeneity after heating, were chosen. The dielectric anomaly was observed when measured with in teq of 600 s and 900 s with Tini = 180 K, suggesting the emergence of a noble metastable state with a high dielectric permittivity.抄録全体を表示PDF形式でダウンロード (1070K)
解説
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髙城 大輔, 須藤 孝一2021 年 48 巻 1 号 p. 17-22
発行日: 2021/01/25
公開日: 2022/06/20
ジャーナル フリーWe provide an analysis of "on-surface polymerization" for a diacetylene (DA) compound 10,12-pentacosadiyn-1-ol (PCDYol) by scanning probe microscopy. For monomolecular layers of the PCDYol on graphite, it is known that two different two-dimensional polymorphic forms—herringbone (H) and parallel (P) arrangements—are observable at room temperature. The chain polymerization of the PCDYol forms the conjugated polydiacetylene (PDA), which is expected to work as the nanowire for the molecular devices. Here, we study the thermodynamic stability of these polymorphs. As a result, we find that the P arrangement is the stable structure while the H arrangement is the quasi-stable one. We also show that the melting point of the P arrangement is 20 ºC higher than that of the bulk crystal probably due to the epitaxial alignment of the PCDYol to the graphite lattice. Furthermore, we statistically analyze the polymerization degree of the PDA chains formed by UV irradiation at different temperatures in air. The distributions of the polymerization degree agree well with the prediction from a simple probabilistic model, allowing for addition reaction and deactivation at both the ends of the chain as stochastic events. The estimated activation energies of the addition reaction and deactivation are noticeably different from those of the conventional solid-state polymerization in the bulk crystals of the DA. Thus, we conclude that the graphite surface and O2 gas in air atmosphere drastically affect on the photo-induced chain polymerization of the PCDYol.抄録全体を表示PDF形式でダウンロード (4191K)
フロギストン
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2021 年 48 巻 1 号 p. 23-24
発行日: 2021/01/25
公開日: 2022/06/20
ジャーナル フリーPDF形式でダウンロード (238K)
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