核与电子能损间耦合作用机理及其诱导辐照效应

During ion irradiation process, the nuclear energy loss, electronic energy loss and the coupling between the nuclear and electronic energy losses would induce the micro-structure evolution and irradiation damage, further leading to the irradiation swelling, hardening and embrittlement behaviors in various structural and functional materials. Understanding the physical mechanisms of nuclear energy loss, electronic energy loss, as well as the coupled effects between them is a scientific challenge in the research fields related to ion-solid interactions and irradiation effects. In this project, experimentally, oxide and metal single crystals will be irradiated by energetic ions with wide energy range, and the damage production and evolution will be characterized through complementary techniques. Theoretically, the observed irradiation effects will be analyzed based on the disorder accumulation model, inelastic thermal spike model and molecular dynamics simulations. The displacement damage originating from the elastic collisions between moving ion and target atomic nuclei, and the thermal spike response originating from the inelastic collisions between moving ion and target electrons will be studied in detail, and then, the synergistic and competitive effects between them on ion-irradiation damage production and evolution will be further demonstrated. Based on the synergistic effect, the displacement damage induced by nuclear energy loss could effectively enhance the thermal spike response to the electronic energy loss, significantly increase the lattice temperature and finally lead to the latent track formation, which could provide a novel path to fabricate nano structure, and therefore promote the research and applications of ion irradiation in various fields.

离子辐照核与电子能损作用过程及其诱导辐照效应，是离子与固体相互作用、材料辐照效应等领域一个基础与重要的科学问题。对该问题的系统研究与理论阐述，是明晰各类传统与新型、结构与功能材料在辐照环境下微观损伤与宏观性能等演变机制的基础。本项目以氧化物与金属单晶为研究对象，通过离子辐照与损伤分析，以disorder accumulation、inelastic thermal spike等物理模型为基础，结合DL_POLY等分子动力学模拟，对核能损诱导离位损伤、电子能损诱导热峰响应、以及两者间耦合诱导损伤时的协同与竞争效应等，进行研究与阐述。通过对核核间弹性碰撞、核与电子间非弹性碰撞诱导晶格温度演变等辐照基本作用过程的探究，分析材料离位损伤特性、热峰响应特性等，探讨能损诱导损伤演变的内在规律与影响因素；以上述辐照效应的基础研究结果为依据，本项目也将为辐照技术的实际应用提供新的研究思路与技术手段。

在辐照效应、核技术应用等领域，伴随着几十eV至数GeV载能离子的应用以及新型复杂物质结构的引入，对离子与固体相互作用机制的深层次理解以及对新现象、新效应、新用途的探索，已成为能源、宇航、信息等前沿领域的共性关键基础支撑。本项目围绕能损的基本作用过程诱导损伤形成以及物性演化的物理机制这一基础科学问题，通过实验、计算、理论相结合，取得的研究结果主要包括：.（i）首次引入原子能量与温度阈值概念，构建辐照参数与径迹损伤的内在关联.基于辐照能量在电子与晶格系统中的沉积传递及其诱导温度的时空演变，揭示了单晶阳离子半径以及热力学等关键参数在径迹形成与再结晶效应中起到的决定性作用；提出描述径迹损伤的原子能量与晶格温度阈值概念，解决单一电子能损参量无法全面描述径迹损伤这一科学问题，实现辐照领域大量研究数据的系统归纳分析。.（ii）深入揭示核与电子能损在诱导辐照损伤时的协同与竞争等耦合效应.通过对核与核弹性碰撞、核与电子非弹性碰撞等辐照基本作用过程的研究，以核与电子能损的作用机制以及固体缺陷理论等为基础，概括阐述了能损之间的耦合作用过程及诱导损伤时的协同与竞争等效应机制，为理解复杂辐照环境下非线性损伤过程提供了基础理论模型与实验数据支撑。.（iii）基于辐照开展微纳制备与物性调控研究，探索核技术与多学科交叉融合.围绕不同能区加速器，发挥辐照能量传递和离子质量沉积在纳米尺度精确可控的优势，精细制备出多种微纳结构（纳米点、通道、颗粒等），调控辐照微区物性（能带、荧光、光电等），为辐照与超滤分离、盐差发电、能源存储等多学科前沿领域的交叉融合提供研究思路与技术支撑。.基于上述系列研究成果，以本项目为第一标注、项目主持人为通讯作者、项目承担单位为第一单位，在Adv. Funct. Mater., Nano Today, J. Mater. Sci. Technol., Mater. Design, Appl. Surf. Sci.等学术期刊发表论文12篇；数次在辐照效应与核技术等领域学术会议上汇报研究成果；参与项目研究的2名博士研究生，获得2次山东大学校长奖学金、3次研究生国家奖学金，一名博士生入选学校特别资助类博士后计划等。