Compression Induced Deformation Twinning Evolution in Liquid-Like Cu2Se,ACS Applied Materials & Interfaces

当前位置： X-MOL 学术 › ACS Appl. Mater. Interfaces › 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.)

Compression Induced Deformation Twinning Evolution in Liquid-Like Cu2Se
ACS Applied Materials & Interfaces ( IF 8.3 ) Pub Date : 2022-04-13 , DOI: 10.1021/acsami.2c00437
Ben Huang ₁ , Guodong Li _{2,

3} , Chenyang Xiao _{2,

3} , Bo Duan _{2,

3} , Wenjuan Li _{2,

3} , Pengcheng Zhai _{1,

3} , William A Goddard ₄

Affiliation

For practical applications of copper selenide (Cu₂Se) thermoelectric (TE) materials with liquid-like behavior, it is essential to determine the structure–property relations as a function of temperature. Here, we investigate β-Cu₂Se structure evolution during uniaxial compression over the temperature range of 400–1000 K using molecular dynamics simulations. We find that at temperatures above 800 K, Cu₂Se exhibits poor stability with breaking order that is described as a liquid-like or hybrid structure comprising a rigid Se sublattice and mobile Cu ions. A uniaxial load causes accumulated structural heterogeneity that is alleviated by diffusion-induced accommodation of local deformations. With increasing strain, the deformation mode changes into a combination of compression and shear, accompanied by restructuring in terms of twinning. Interestingly, in addition to a plastic behavior rarely found in inorganic semiconductors, we find that higher temperature promotes deformation twinning in liquid-like Cu₂Se, showing the role of thermal instability, including Cu diffusion, in structural adaptation and mechanical modulation. These findings reveal the micromechanism of hybrid structural evolution as well as performance tuning through twinning, which provides a theoretical guide toward advanced Cu₂Se TE materials design.

中文翻译：

类液体 Cu2Se 中的压缩变形孪晶演化

对于具有类液体行为的硒化铜 (Cu ₂ Se) 热电 (TE) 材料的实际应用，必须确定随温度变化的结构-性能关系。在这里，我们使用分子动力学模拟研究了 400-1000 K 温度范围内单轴压缩过程中的β-Cu _{2 Se 结构演变。}我们发现在 800 K 以上的温度下，Cu ₂Se 表现出较差的破坏顺序，其被描述为包含刚性 Se 亚晶格和可移动 Cu 离子的液体状或混合结构。单轴载荷会导致累积的结构异质性，通过扩散引起的局部变形调节来缓解这种异质性。随着应变的增加，变形模式转变为压缩和剪切的组合，伴随着孪晶方面的重组。有趣的是，除了在无机半导体中很少发现的塑性行为外，我们发现较高的温度会促进液态 Cu _{2中的变形孪晶}Se，显示了热不稳定性（包括 Cu 扩散）在结构适应和机械调制中的作用。这些发现揭示了混合结构演化的微观机制以及通过孪晶进行的性能调整，为先进的 Cu ₂ Se TE 材料设计提供了理论指导。

更新日期：2022-04-13

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南