Glass Transition and Crystallization in Hexagonal Boron Nitride: Crucial Role of Orientational Order,Advanced Theory and Simulations

当前位置： X-MOL 学术 › Adv. Theory Simul. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Glass Transition and Crystallization in Hexagonal Boron Nitride: Crucial Role of Orientational Order
Advanced Theory and Simulations ( IF 2.9 ) Pub Date : 2019-11-18 , DOI: 10.1002/adts.201900174
R. Ravinder ₁ , Prateet Garg ₁ , N. M. Anoop Krishnan _{1,

2}

Affiliation

While extensive studies have been carried out on 2D crystals, their disordered counterpart, namely 2D glasses, remain poorly explored. Using molecular dynamics simulation, it is demonstrated that hexagonal boron nitride (h‐BN) can exhibit crystallization and glass transition. Similar to archetypical glasses, it is observed that the glassy structures are disordered, marked by the absence of any long‐range order while exhibiting some short‐range order. Further, the structures obtained are stable in three dimensions, confirming the realistic nature of the 2D glasses. Interestingly, it is observed that the orientational order of the h‐BN structure with respect to density as well as ground state enthalpy follows a master curve for both crystallization and glass transition, revealing thermally accessible regions for the structure. Further, the standard deviation of orientational order provides information about the spatial heterogeneity in the structure, the rearrangement of which results in the formation of crystal/glass. This suggests that the orientational order may play a crucial role in controlling the propensity for crystallization/glass transition in systems having directional bonds.

中文翻译：

六方氮化硼中的玻璃化转变和结晶：取向顺序的关键作用

尽管已经对2D晶体进行了广泛的研究，但对它们无序的对应物（即2D眼镜）的探索仍然很少。使用分子动力学模拟，证明六方氮化硼（h-BN）可以显示结晶和玻璃化转变。与原型玻璃类似，可以观察到玻璃状结构是无序的，其特征是没有任何长距离有序，而表现出一些短距离有序。此外，所获得的结构在三个维度上都是稳定的，证实了2D眼镜的真实性。有趣的是，观察到h-BN结构相对于密度以及基态焓的取向顺序遵循结晶和玻璃化转变的主曲线，揭示了该结构的热可及区域。进一步，取向顺序的标准偏差提供了有关结构中空间异质性的信息，其重排导致晶体/玻璃的形成。这表明在具有方向键的体系中，取向顺序可能在控制结晶/玻璃化转变的倾向中起关键作用。

更新日期：2020-03-04

点击分享查看原文

点击收藏

阅读更多本刊最新论文