日本結晶成長学会誌
Online ISSN : 2187-8366
Print ISSN : 0385-6275
ISSN-L : 0385-6275
44 巻 , 2 号
選択された号の論文の9件中1~9を表示しています
特集:「テンプレートを利用した機能性材料の形態制御」
特集序文
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解説
  • 定金 正洋, Zhenxin Zhang, 上田 渉
    2017 年 44 巻 2 号 p. 74-81
    発行日: 2017年
    公開日: 2017/10/18
    ジャーナル フリー

      Synthesis of novel crystalline metal oxides by assembly of polyoxometalate building blocks is presented. Polyoxometalates, anionic metal oxide clusters of early transition metals such as tungsten (W) and molybdenum (Mo) with variety of structures in controlled mater, interact or make bonds with cationic species to form crystalline metal oxides. Here, we describes our four results. 1) Formation of microporous material by assembly of in-situ produced α-Keggin-type phosphotungstate with ammonium cation. 2) Formation of molecular nanowires based crystalline metal oxides by assembly of tellurium (Te) and selenium (Se) with W and Mo. 3) Formation of Mo-vanadiuim (V) oxides by assembly of pentagonal polyoxomolybdate with other Mo and V. 4) Formation of micropores Mo-V-bithmus (Bi) oxide and Mo-M (M = manganese (Mn), zinc (Zn), iron (Fe), and cobalt (Co)) by assembly of ε-Keggin-type heteropolymolybdates with cationic elements. Applications as catalysts and adsorption materials are also presented.

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解説
  • 山田 哲也, 鈴木 清香, 是津 信行, 手嶋 勝弥
    2017 年 44 巻 2 号 p. 88-95
    発行日: 2017年
    公開日: 2017/10/18
    ジャーナル フリー

      Shape controls of primary and secondary particles, which mean the design of crystals, including atomic building, shape control, particle connection, and crystal alignment, is one of dominant factors to determine functional abilities of materials, since the material performances do not only depend on chemical compositions and structures, but also crystallographic characteristics. For improvements of advanced materials use, development of innovative morphologic-control techniques should be an important issue. We have studied crystal growths by using flux method, which is liquid-phase growth technique, to provide high crystalline, unconventional shape of functional materials. As one of strategic application of flux method for shape control, we introduced template-mediated flux crystal growths, which exhibit unique shapes in terms of their primary and secondary appearances.

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  • 野澤 純, 郭 素霞, 胡 素梦, 豊玉 彰子, 山中 淳平, 小泉 晴比古, 岡田 純平, 宇田 聡
    2017 年 44 巻 2 号 p. 96-102
    発行日: 2017年
    公開日: 2017/10/18
    ジャーナル フリー

      The two-dimensional (2D) nucleation is the predominant growth mechanisms for colloidal crystals whose particle interaction is attractive. The colloidal crystallization in the attractive system has recently been regarded as a promising method to fabricate varieties of complex nano-structures possessing innovative functionality. In the present study, polymers are added to a colloidal suspension to generate a depletion attractive force, and the detailed 2D nucleation process on the terrace of the colloidal crystals is investigated. We first measured the nucleation rate at various area fractions of particles on the terrace, φarea. In situ observations at single-particle resolution enable us to measure the steady-state homogeneous 2D nucleation rate, J, and the critical size of nuclei, r*, and the relationship between them and φarea is found to agree well with classical nucleation theory (CNT). The step free energy, γ, derived from the nucleation theory is found to vary according to the strength of attraction, which is tuned by the concentration of the polymer as a depletant.

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