Banhart Florian
Institut de Physique et Chimie des Matériaux, UMR 7504, Université de Strasbourg, CNRS, Strasbourg, 67034, France.
Small. 2025 Jul;21(28):e2310462. doi: 10.1002/smll.202310462. Epub 2024 May 3.
Low-dimensional materials based on graphene or graphite show a large variety of phenomena when they are subjected to irradiation with energetic electrons. Since the 1990s, electron microscopy studies, where a certain irradiation dose is unavoidable, have witnessed unexpected structural transformations of graphitic nanoparticles. It is recognized that electron irradiation is not only detrimental but also bears considerable potential in the formation of new graphitic structures. With the availability of aberration-corrected electron microscopes and the discovery of techniques to produce monolayers of graphene, detailed insight into the atomic processes occurring during electron irradiation became possible. Threshold energies for atom displacements are determined and models of different types of lattice vacancies are confirmed experimentally. However, experimental evidence for the configuration of interstitial atoms in graphite or adatoms on graphene remained indirect, and the understanding of defect dynamics still depends on theoretical concepts. This article reviews irradiation phenomena in graphene- or graphite-based nanomaterials from the scale of single atoms to tens of nanometers. Observations from the 1990s can now be explained on the basis of new results. The evolution of the understanding during three decades of research is presented, and the remaining problems are pointed out.
基于石墨烯或石墨的低维材料在受到高能电子辐照时会呈现出多种现象。自20世纪90年代以来，电子显微镜研究（在该研究中一定的辐照剂量不可避免）见证了石墨纳米颗粒意外的结构转变。人们认识到电子辐照不仅具有破坏性，而且在新石墨结构的形成中具有相当大的潜力。随着像差校正电子显微镜的出现以及制备单层石墨烯技术的发现，详细了解电子辐照过程中发生的原子过程成为可能。确定了原子位移的阈值能量，并通过实验证实了不同类型晶格空位的模型。然而，关于石墨中间隙原子的构型或石墨烯上吸附原子的实验证据仍然是间接的，对缺陷动力学的理解仍然依赖于理论概念。本文回顾了从单原子尺度到几十纳米尺度的基于石墨烯或石墨的纳米材料中的辐照现象。现在可以根据新的结果来解释20世纪90年代的观察结果。展示了三十年来研究过程中的认识演变，并指出了仍然存在的问题。
