Mechanism of Al Coordination Change in Alkaline-earth Aluminosilicate Glasses: An Application of Bond Valence Model

DOI Web Site Web Site 37 References
  • Sukenaga Sohei
    Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University
  • Kanehashi Koji
    Nippon Steel Technology Co., Ltd.
  • Yamada Hiroki
    Japan Synchrotron Radiation Research Institute (SPring-8/JASRI)
  • Ohara Koji
    Japan Synchrotron Radiation Research Institute (SPring-8/JASRI) Faculty of Materials for Energy, Shimane University
  • Wakihara Toru
    Institute of Engineering Innovation, School of Engineering, The University of Tokyo
  • Shibata Hiroyuki
    Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University

Bibliographic Information

Other Title
  • アルカリ土類アルミノケイ酸塩ガラスにおけるアルミニウムイオンの酸素配位数変化機構:Bond valenceモデルの応用
  • アルカリドルイ アルミノケイ サンエン ガラス ニ オケル アルミニウムイオン ノ サンソ ハイイスウ ヘンカ キコウ : Bond valence モデル ノ オウヨウ

Search this article

Abstract

<p>Aluminum cations are generally present in four-fold ([4]Al3+) or five-fold coordination ([5]Al3+) in aluminosilicate slags, where the concentration of [5]Al3+ varies depending on the type of charge compensator, for example, Mg2+ and Ca2+. Although it has been reported that the amount of [5]Al3+ species increases with the replacement of CaO with MgO in the CaO–MgO–SiO2–Al2O3 system, the detailed mechanism underlying the change in the local structure near the aluminum cations remains unclear. Because the residual negative charge on the bridging oxygen between [4]Si4+ and [5]Al3+ ([4]Si4+–OBO–[5]Al3+) is larger than that of [4]Si4+–OBO–[4]Al3+, it is essential to understand the positive charge contributions of alkaline-earth cations to compensate for these negative charges on the bridging oxygens. In the present study, the valence of a single chemical bond near Mg2+ and Ca2+ cations in the chosen aluminosilicate glasses was determined using a simple empirical model, which enabled calculation of the bond valence from the observed interatomic distance of near alkaline-earth cations by synchrotron X-ray total scattering. Magnesium cations had a larger average bond valence (+0.39) than calcium cations (+0.31). The difference in the positive charge contribution from Mg2+ and Ca2+ should explain the variation in the coordination number of aluminum cations.</p>

Journal

  • Tetsu-to-Hagane

    Tetsu-to-Hagane 109 (11), 934-939, 2023-11-01

    The Iron and Steel Institute of Japan

References(37)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top