Rojano Andrés, Hunt R J, Crocombette J-P, Murphy S T
Department of Engineering, Lancaster University, Lancaster LA1 4YW, United Kingdom.
Université Paris-Saclay, CEA, Service de recherche en Corrosion et du Comportement des Matériaux, SRMP, F-91191 Gif-sur-Yvette, France.
J Phys Condens Matter. 2024 May 22;36(33). doi: 10.1088/1361-648X/ad4941.
Two-Temperature molecular dynamics (2T-MD) is a common approach for describing how electrons contribute to the evolution of a damage cascade by addressing their role in the redistribution of energy in the system. However, inaccuracies in 2T-MD's treatment of the high-energy particles have limited its utilisation. Here, we propose a reformulation of the traditional 2T-MD scheme to overcome this limitation by addressing the spurious double-interaction of high-energy atoms with electrons. We conduct a series of radiation damage cascades for 30, 50, and 100 keV primary knock-on atoms in increasingly large cubic W cells. In the simulations, we employ our modified 2T-MD scheme along with other treatments of electron-phonon coupling to explore their impact on the cascade evolution and the number of remnant defects. The results suggest that with the proposed modification, 2T-MD simulations account for the temperature time evolution during the ballistic phase and remove arbitrary choices, thus providing a better description of the underlying physics of the damage process.
双温分子动力学（2T-MD）是一种常用方法，通过研究电子在系统能量重新分布中的作用来描述电子如何影响损伤级联的演化。然而，2T-MD对高能粒子处理的不准确限制了其应用。在此，我们提出对传统2T-MD方案进行重新制定，通过解决高能原子与电子的虚假双相互作用来克服这一限制。我们在越来越大的立方钨晶胞中对能量为30 keV、50 keV和100 keV的初级撞出原子进行了一系列辐射损伤级联模拟。在模拟中，我们采用改进后的2T-MD方案以及其他电子-声子耦合处理方法，以探究它们对级联演化和残余缺陷数量的影响。结果表明，通过所提出的改进，2T-MD模拟能够考虑弹道阶段的温度时间演化并消除任意选择，从而更好地描述损伤过程的基础物理机制。
