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arXiv 2402.04726cond-mat.mtrl-sci
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通过高通量从头计算研究MAB相的相稳定性与力学性能趋势

Phase stability and mechanical property trends for MAB phases by high-throughput ab initio calculations

Nikola Koutná, Lars Hultman, Paul H. Mayrhofer, Davide G. Sangiovanni

AI总结:

本研究通过高通量从头计算筛选多种元素与化学计量比构成的MAB相,分析其相稳定性、相变增韧潜力与各向异性力学性能,识别出Nb₃AlB₄等多种高潜力材料,为MAB相的实验合成与应用提供理论指导。

摘要:

MAB相(MABs)是类陶瓷/类金属层构成的原子级薄层状材料,在二维材料发展中取得了突破。尽管理论上拥有广阔的化学与相空间,但目前已合成的MAB相相对较少。为指导实验,我们对由4-7族过渡金属(M)、铝/硅/镓/锗/铟(A)与硼(B)构成的MAB相开展了系统的高通量从头计算筛选,重点研究其相稳定性趋势与力学性能。考虑1:1:1、2:1:1、2:1:2、3:1:2、3:1:3、3:1:4的M:A:B化学计量比与10种相原型,我们通过竞争相的力学与动力学稳定MAB相的形成能谱,评估每种元素组合形成单相化合物的可能性。基于能量相近相的体积接近度,我们识别出体积变化形变可促进相变增韧的体系。随后,我们利用基于弹性常数的描述符,预测了与化学组成和相结构相关的弹性刚度与延展性趋势。通过分析各向异性柯西压力与杨氏模量,我们对比了平行于和垂直于M-B/A层方向的力学响应。研究提出的最具潜力的MAB相包括Nb₃AlB₄、Cr₂SiB₂、Mn₂SiB₂以及已合成的MoAlB。

英文摘要:

MAB phases (MABs) are atomically-thin laminates of ceramic/metallic-like layers, having made a breakthrough in the development of 2D materials. Though theoretically offering a vast chemical and phase space, relatively few MABs have yet been synthesised. To guide experiments, we perform a systematic high-throughput {\it{ab initio}} screening of MABs that combine group 4--7 transition metals (M); Al, Si, Ga, Ge, or In (A); and boron (B) focusing on their phase stability trends and mechanical properties. Considering the 1:1:1, 2:1:1, 2:1:2, 3:1:2, 3:1:3, and 3:1:4 M:A:B ratios and 10 phase prototypes, possible stabilisation of a single-phase compound for each elemental combination is assessed through formation energy spectra of the competing mechanically and dynamically stable MABs. Based on the volumetric proximity of energetically-close phases, we identify systems in which volume-changing deformations may facilitate transformation toughening. Subsequently, chemistry- and phase-structure-related trends in the elastic stiffness and ductility are predicted using elastic-constants-based descriptors. The analysis of directional Cauchy pressures and Young's moduli allows comparing mechanical response parallel and normal to M--B/A layers. Among the suggested most promising MABs are Nb$_3$AlB$_4$, Cr$_2$SiB$_2$, Mn$_2$SiB$_2$ or the already synthesised MoAlB.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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