Understanding diffraction patterns of glassy, liquid and amorphous materials via persistent homology analyses
Understanding diffraction patterns of glassy, liquid and amorphous materials via persistent homology analyses
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DOI：
10.2109/jcersj2.19143
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发表时间：
2019-12-01
影响因子：
1.1
通讯作者：
Sakata, Osami
中科院分区：
文献类型：
--
作者：
Onodera, Yohei;Kohara, Shinji;Sakata, Osami
由于衍射数据的结构信息不足，玻璃态、液态和无定形材料的结构仍然没有得到很好的理解。在这篇文章中，试图了解衍射峰的起源，特别是第一个尖锐的衍射峰（FSDP，Q（1）），主峰（PP，Q（2）），和第三个峰（Q（3）），观察到的衍射图案的无序材料，其结构包含四面体图案。证实了FSDP（Q（1））不是网络形成的标志，因为在四面体分子液体中观察到FSDP。发现PP（Q（2））反映了四面体的取向相关性。Q（3），可以在所有无序材料中观察到，甚至在常见的液态金属中，源于简单的对相关。此外，无序材料的拓扑结构的信息，揭示了利用持久的同源性分析。二氧化硅（SiO2）玻璃的持久性图表明，玻璃中的环的形状不仅类似于具有可比密度的晶相（α-方石英）中的环，而且类似于具有较高密度的晶相（α-石英和柯石英）中存在的环;这被认为是无序的特征。此外，我们已经成功地揭示了差异，在持久的同源性，四面体网络和四面体分子液体之间，液体和非晶（玻璃态）状态之间的差异/相似性。我们的一系列分析表明，衍射数据和持久的同源性分析的组合是一个有用的工具，让我们发现隐藏在无序材料的晕模式的结构特征。(C)2019年日本陶瓷协会。All rights reserved.
The structure of glassy, liquid, and amorphous materials is still not well understood, due to the insufficient structural information from diffraction data. In this article, attempts are made to understand the origin of diffraction peaks, particularly of the first sharp diffraction peak (FSDP, Q(1)), the principal peak (PP, Q(2)), and the third peak (Q(3)), observed in the measured diffraction patterns of disordered materials whose structure contains tetrahedral motifs. It is confirmed that the FSDP (Q(1)) is not a signature of the formation of a network, because an FSDP is observed in tetrahedral molecular liquids. It is found that the PP (Q(2)) reflects orientational correlations of tetrahedra. Q(3), that can be observed in all disordered materials, even in common liquid metals, stems from simple pair correlations. Moreover, information on the topology of disordered materials was revealed by utilizing persistent homology analyses. The persistence diagram of silica (SiO2) glass suggests that the shape of rings in the glass is similar not only to those in the crystalline phase with comparable density (alpha-cristobalite), but also to rings present in crystalline phases with higher density (alpha-quartz and coesite); this is thought to be the signature of disorder. Furthermore, we have succeeded in revealing the differences, in terms of persistent homology, between tetrahedral networks and tetrahedral molecular liquids, and the difference/similarity between liquid and amorphous (glassy) states. Our series of analyses demonstrated that a combination of diffraction data and persistent homology analyses is a useful tool for allowing us to uncover structural features hidden in halo pattern of disordered materials. (C) 2019 The Ceramic Society of Japan. All rights reserved.