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arXiv 2301.06554cond-mat.mtrl-scicond-mat.dis-nn

基于描述符的广阔化学空间高熵材料理性设计

Descriptor-Enabled Rational Design of High-Entropy Materials Over Vast Chemical Spaces

Dibyendu Dey, Liangbo Liang, Liping Yu

AI总结:

本文提出混合焓-熵描述符MEED,基于第一性原理揭示高熵材料稳定性判据与熵形成能力评估方法,实现高通量筛选并预测多种新型碳化物和二维硫化物。

摘要:

高熵材料(HEM)实际上无限的高维成分空间已成为功能材料设计与发现的一个令人振奋的平台。然而,由于难以确定特定成分和结构的焓与熵对HEM稳定性及形成的贡献,识别稳定且可合成的HEM以及稳健的设计规则仍是一项艰巨挑战。本工作中,利用第一性原理计算,我们发现:(i)HEM的稳定性和混溶性强烈取决于HEM相对于最稳定竞争相的形成焓,而非传统所认为的相对于所有可能竞争相的混合焓;(ii)HEM的熵形成能力可通过有序二元化合物中数十个替位缺陷的缺陷形成能谱来衡量,无需对大量合金构型进行采样。基于这些发现,我们提出了具有高度预测性的混合焓-熵描述符(Mixed Enthalpy-Entropy Descriptor,MEED),它能够在广阔化学空间中对新型HEM进行理性的高通量第一性原理设计与筛选。将MEED应用于两种结构截然不同的材料体系(即三维岩盐型碳化物和二维层状硫化物),不仅成功识别出每个体系中所有经实验报道的HEM,还揭示了评估其相对可合成性的通用截断判据。此外,还预测了数十种新型高熵碳化物和二维高熵硫化物。它们在航空航天器件涂层、能量转换与存储以及柔性电子等多种应用中具有潜力。

英文摘要:

The practically unlimited high-dimensional composition space of high-entropy materials (HEMs) has emerged as an exciting platform for functional materials design and discovery. However, the identification of stable and synthesizable HEMs and robust design rules remains a daunting challenge due to the difficulty in determining composition/structure-specific enthalpy and entropy contributions to the stability and formation of HEMs. In this work, using first-principles calculations, we find that (i) the stability and miscibility of HEMs strongly depend on the formation enthalpy of the HEM relative to the most stable completing phase rather than on the conventionally-viewed enthalpies of mixing over all possible competing phases, and (ii) the entropy forming ability of a HEM can be measured from the defect formation energy spectrum of tens of substitutional defects in ordered binary compounds, involving no sampling over numerous alloy configurations. Based on these findings, we propose a highly predictive Mixed Enthalpy-Entropy Descriptor (MEED), which enables the rational high-throughput first-principles design and screening of new HEMs over large chemical spaces. Applying the MEED to two structurally distinct material systems (i.e., 3D rocksalt carbides and 2D layered sulfides), not only all experimentally reported HEMs within each system are successfully identified, but a universal cutoff criterion for assessing their relative synthesizability also revealed. In addition, tens of new high entropy carbides and 2D high-entropy sulfides are also predicted. They have the potential for a wide variety of applications such as coating in aerospace devices, energy conversion and storage, and flexible electronics.

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