Energies and structures of Cu/Nb and Cu/W interfaces from density functional theory and semi-empirical calculations
Energies and structures of Cu/Nb and Cu/W interfaces from density functional theory and semi-empirical calculations
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DOI：
10.1016/j.mtla.2022.101362
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发表时间：
2022-02-27
期刊：
影响因子：
3.4
通讯作者：
Romaner, L.
中科院分区：
文献类型：
--
作者：
Bodlos, R.;Fotopoulos, V;Romaner, L.
Cu/Me多层系统，其中Me指的是体心立方（bcc）金属，例如Nb和W，广泛用于核、电气和电子应用。尽管仅占体积的一小部分，但此类系统中的界面在确定其电、机械、热和扩散特性方面发挥着重要作用。面心立方（fcc）Cu通常与bcc金属或其变体形成Kurdjumov-Sachs（KS）和Nishiyama-Wassermann（NW）型界面。对于Cu/Nb系统，这些界面关系已被广泛研究的半经验方法。令人惊讶的是，能量学和界面性质的Cu/W尚未被详细研究，尽管广泛的应用。在这项研究中，我们采用周期性嵌入原子方法（EAM）和密度泛函理论（DFT）模拟探索的几何和能量特性的KS和NW界面的Cu/Nb和Cu/W。为了评估我们的方法的可靠性，周期性细胞的大小上的结果的依赖性检查相干和非相干接口。我们提供的界面能和分离的Cu/W和Cu/Nb界面的DFT精度的工作。两个EAM势的计算结果与使用DFT得到的结果定性一致，并允许调查界面性质的收敛性。这些关键的能量可以用于未来的热力学和力学建模的Cu/Me界面。
Cu/Me multilayer systems, with Me referring to a body-centered cubic (bcc) metal, such as Nb and W, are widely used for nuclear, electrical, and electronic applications. Despite making up only a small percentage of the volume, interfaces in such systems play a major role in determining their electrical, mechanical, thermal and diffusive properties. Face-centered cubic (fcc) Cu often forms Kurdjumov-Sachs (KS) and Nishiyama-Wassermann (NW) type interfaces with bcc metals or variations thereof. For the Cu/Nb system, these interface relationships have been extensively studied with semi-empirical methods. Surprisingly, the energetics and interface properties of Cu/W have not yet been studied in detail, in spite of extensive applications. In this study, we employ both periodic Embedded Atom Method (EAM) and Density Functional Theory (DFT) simulations to explore the geometric and energetic properties of the KS and NW interfaces of Cu/Nb and Cu/W. To assess the reliability of our approach, the dependence of the results on the size of periodic cells is examined for coherent and incoherent interfaces. We provide the interface energies and the work of separation for the Cu/W and Cu/Nb interfaces at DFT accuracy. The results of calculations with two EAM potentials are in qualitative agreement with those obtained using DFT and allow investigating the convergence of interfacial properties. These key energetic quantities can be used for future thermodynamic and mechanical modeling of Cu/Me interfaces.