金属/氮化物纳米多层膜氦离子辐照的界面效应研究

The safety, reliability, and efficiency of nuclear energy system depend on the development of high-performance, radiation-resistant materials. Recently several nanoscale multilayers are found to exhibit improved radiation damage tolerant properties. Interfaces play a major role on the recovery of radiation damage in those multilayers, and the mechanism for interactions between Helium and layer interfaces is the key scientific problem that remained to be resolved. This project will focus on exploring the role of interface in determining the irradiation properties of nanoscale metal/nitride multilayer systems. Helium ion implantation will be used to evaluate the irradiation properties of the multilayers. Through proper selection of multilayer systems, the atomic structure and composition of interfaces can be varied by design. By the employment of high resolution transmission electron microscope, neutron reflectometry analysis and other techniques, the interface structure and chemical properties will be examined at atomic level to reveal of process of trapping, transportation and growth of Helium on the metal/nitride interfaces. The influence of interface atomic structure and chemical properties on the mechanism of Helium-interface interactions will be further examined by the combination of first principle calculation and molecular dynamics simulation. This project will contribute to the understanding of interface role on radiation damage behavior of nano-structured materials at atomic level, and provide guidelines for the design of novel high-performance, radiation-resistant materials.

安全、高效和可靠地利用核能的一个关键在于提高结构材料抗辐照损伤的能力，最近一些研究发现纳米多层材料具有优异的抗辐照损伤性能。界面对纳米多层材料的辐照损伤行为有着重要的影响，研究氦与界面的相互作用机制是其中一个关键的科学问题。本项目以纳米尺度的金属/氮化物多层膜为研究对象，采用氦离子注入方法对其抗辐照损伤性能进行研究。本项目拟通过选取合适的材料体系制备出界面结构和化学成分可控的纳米多层膜，采用高分辨电镜观察和中子反射分析等多种手段对引入氦前后金属/氮化物界面的原子结构和成分进行细致的表征和分析，研究氦在金属/氮化物界面上的捕获、聚集和长大等物理过程，结合第一性原理计算和分子动力学模拟，获得界面结构和化学成分对氦与金属/氮化物界面相互作用机制的影响规律。研究结果将有助于在原子尺度上深入理解界面效应对纳米结构材料辐照损伤行为的影响，有望为新型高强度耐辐照损伤的结构材料的设计提供理论依据。