The quest for a bidirectional auxetic, elastic, and enhanced fracture toughness material: Revisiting the mechanical properties of the BeH2 monolayers,Journal of Computational Chemistry

当前位置： X-MOL 学术 › J. Comput. Chem. › 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.)

The quest for a bidirectional auxetic, elastic, and enhanced fracture toughness material: Revisiting the mechanical properties of the BeH2 monolayers
Journal of Computational Chemistry ( IF 3.4 ) Pub Date : 2022-04-28 , DOI: 10.1002/jcc.26875
Armando A Morin-Martinez ₁ , Jessica Arcudia ₁ , Ximena Zarate ₂ , Miguel Eduardo Cifuentes-Quintal ₁ , Gabriel Merino ₁

Affiliation

Herein we show a density functional theory-based study performed on two recently predicted polymorphs of the BeH₂ monolayer, α-BeH₂ and β-BeH₂. The α-BeH₂ phase possesses an in-plane negative Poisson's ratio (NPR), introducing it into the unique group of auxetic materials. Our assessment delves into the linear-elastic and finite-strain regimes to understand both polymorphs' structural and mechanical responses to deformation. We find that the in-plane NPR is shown to be only parallel to the bonds in α-BeH₂ and remains along the uniaxial tensile path. Concomitantly, an out-of-plane transition toward auxetic is also revealed in regions exhibiting conventional Poisson's ratios, making α-BeH₂ a bidirectionally auxetic material. While phase transitions in β-BeH₂ are triggered at very short strains, α-BeH₂ displays excellent elasticity against tension, superior to that of most currently known 2D materials.

中文翻译：

寻求双向拉胀、弹性和增强的断裂韧性材料：重新审视 BeH2 单层膜的机械性能

_{在此，我们展示了对 BeH 2}单层的两种最近预测的多晶型物 α-BeH ₂和 β-BeH ₂进行的基于密度泛函理论的研究。α-BeH ₂相具有面内负泊松比 (NPR)，将其引入独特的拉胀材料组。我们的评估深入研究了线性弹性和有限应变机制，以了解多晶型物对变形的结构和机械响应。我们发现面内 NPR 显示仅平行于 α-BeH ₂中的键并且保持沿着单轴拉伸路径。同时，在表现出传统泊松比的区域中也揭示了向拉胀的平面外过渡，使 α-BeH ₂一种双向拉胀材料。虽然 β-BeH ₂中的相变是在非常短的应变下触发的，但 α-BeH ₂表现出出色的抗张力弹性，优于大多数目前已知的二维材料。

更新日期：2022-04-28

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11