Ion irradiation and modification: The role of coupled electronic and nuclear energy dissipation and subsequent nonequilibrium processes in materials
Ion irradiation and modification: The role of coupled electronic and nuclear energy dissipation and subsequent nonequilibrium processes in materials
复制标题
离子辐照和改性：材料中耦合的电子和核能耗散及随后的非平衡过程的作用
DOI：
10.1063/5.0027462
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发表时间：
2020-11
影响因子：
15
通讯作者：
Yanwen Zhang;W. J. Weber
中科院分区：
文献类型：
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作者：
Yanwen Zhang;W. J. Weber
理解材料对高能带电粒子能量沉积的响应对于缺陷工程、离子束加工、离子束分析与改性、地质老化、太空探索以及核应用都非常重要。当入射离子穿透固体时，其能量会传递给固体的电子和原子核。这种电子能量沉积的很大一部分随后会通过电子 - 声子（e - ph）耦合传递给原子结构，导致局部非弹性热峰，其中能量耗散受局部环境影响。此外，强烈的电离可导致宽带隙材料和陶瓷中局域电子激发的高密度，这会影响缺陷动力学和原子迁移率。具体而言，电子与原子核之间的能量交换以及局域电子激发可导致显著的竞争（电离诱导退火）、累加（电子和核能沉积都对损伤产生有贡献）以及协同（比单独损伤过程之和造成更多损伤）效应。尽管在离子 - 固体相互作用过程中，对于预先存在的缺陷和残余损伤，电子 - 声子耦合强度和非热过程的非单调效应已得到证实，但对于在多种材料的损伤产生和演化的原子尺度模型中何时必须考虑此类电子效应，人们的理解还很有限。具有不同组成元素的复杂陶瓷和化学无序固溶体合金能够随着复杂性的增加对缺陷动力学和辐照性能进行系统评估。本文综述了有关调节键合特性和化学无序以控制原子级动力学的现有知识。尽管缺乏基本理解阻碍了离子束材料改性可靠预测的进展，但它凸显了挑战并开启了研究机遇。对极端能量沉积下复杂的电子和原子相关性的深入了解将增强我们在辐射环境中设计材料和预测离子辐照诱导损伤的能力，并可能为更好地控制基本过程和为先进技术设计新的材料功能铺平道路。
Understanding material responses to energy deposition from energetic charged particles is important for defect engineering, ion-beam processing, ion-beam analysis and modification, geologic aging, space exploration, and nuclear applications. As an incident ion penetrates a solid, its energy is transferred to electrons and to atomic nuclei of the solid. Much of this electronic energy deposition is subsequently transferred to the atomic structure via electron–phonon (e–ph) coupling, leading to local inelastic thermal spikes in which energy dissipation is influenced by the local environment. In addition, intense ionization can lead to high densities of localized electronic excitations in wide-bandgap materials and ceramics that can affect defect dynamics and atomic mobility. Specifically, energy exchange between electrons and atomic nuclei, along with localized electronic excitations, can lead to substantial competitive (ionization-induced annealing), additive (both electronic and nuclear energy depositions contributing to damage production), and synergistic (more damage than the sums of separate damage processes) effects. Although nonmonotonic effects of the e–ph coupling strength and athermal processes are demonstrated for pre-existing defects and residual damage during ion–solid interactions, there is limited understanding of when such electronic effects must be considered in atomic-scale models of damage production and evolution in a broad variety of materials. Complex ceramics and chemically disordered solid solution alloys with different constituent elements allow a systematic evaluation of defect dynamics and irradiation performance with increasing complexity. Current knowledge regarding tuning of bonding characteristics and chemical disorder to control atomic-level dynamics is reviewed. Although a lack of fundamental understanding obstructs the advancement of reliable predictions for ion beam material modification, it highlights challenges and opens research opportunities. Insights into the complex electronic and atomic correlations with extreme energy deposition will strengthen our ability to design materials and predict ion-irradiation-induced damage in a radiation environment, and they may pave the way to better control fundamental processes and design new material functionalities for advanced technologies.