Investigation of the Pd(1-x)Znxalloy phase diagram usingab initiomodelling approaches.
Investigation of the Pd(1-x)Znxalloy phase diagram usingab initiomodelling approaches.
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使用从头建模方法研究 Pd(1-x)Znx 合金相图。
DOI：
10.1088/1361-648x/ace01a
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Kabalan L
中科院分区：
文献类型：
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作者：
Kabalan L
合金材料中稳定相的识别具有挑战性，因为组成影响不同中间相的结构稳定性。通过多尺度建模方法，计算模拟可以显着加速相空间的探索，并有助于识别稳定相。在这里，我们应用这种新的方法来理解复杂的相图的二元合金的PdZn，与结构的多晶型物的相对稳定性，通过应用密度泛函理论与集群扩展（CE）相结合。实验相图有几个竞争的晶体结构，我们专注于三个不同的密堆积相，通常观察到的PdZn，即面心立方（FCC），体心四面体（BCT）和六方密堆积（HCP），以确定其各自的稳定范围。我们的多尺度方法证实了BCT混合合金的稳定性范围很窄，在43.75%至50%的Zn浓度范围内，这与实验观察一致。我们随后使用CE表明，在所有浓度的阶段是竞争性的，但FCC合金相有利于锌浓度低于43.75%，和HCP结构有利于锌丰富的浓度。我们的方法和结果提供了一个平台，为未来的调查PdZn和其他紧密堆积的合金系统与多尺度建模技术。
The identification of the stable phases in alloy materials is challenging because composition affects the structural stability of different intermediate phases. Computational simulation, via multiscale modelling approaches, can significantly accelerate the exploration of phase space and help to identify stable phases. Here, we apply such new approaches to understand the complex phase diagram of binary alloys of PdZn, with the relative stability of structural polymorphs considered through application of density functional theory coupled with cluster expansion (CE). The experimental phase diagram has several competing crystal structures, and we focus on three different closed-packed phases that are commonly observed for PdZn, namely the face-centred cubic (FCC), body-centred tetragonal (BCT) and hexagonal close packed (HCP), to identify their respective stability ranges. Our multiscale approach confirms a narrow range of stability for the BCT mixed alloy, within the Zn concentration range from 43.75% to 50%, which aligns with experimental observations. We subsequently use CE to show that the phases are competitive across all concentrations, but with the FCC alloy phase favoured for Zn concentrations below 43.75%, and that the HCP structure favoured for Zn-rich concentrations. Our methodology and results provide a platform for future investigations of PdZn and other close-packed alloy systems with multiscale modelling techniques.