从单层和少层的石墨烯出发,利用透射电子显微镜中的高能电子束辐照,可控地制备了准二维完全无定形和半无定形碳结构,用高分辨成像和相干的纳米区域电子衍射技术表征了样品结构在高能电子束辐照前后的变化,基于实验记录的电子衍射花样得到了样品的原子对分布函数.分析表明,在所制备的准二维无定形结构中,六元环不再是碳原子的主要排列方式,碳原子的各阶最近邻间距相对于完美石墨烯中的值有所偏离并趋向无序;同时还发现,锯齿型的碳链结构不易被破坏,并使得准二维无定形碳结构中还保留了短程有序和可达0.5 nm的中程有序.%Quasi-2-dimensional total amorphous and half-amorphous carbon structures are fabricated from single-layer or few-layer of graphene via high-energy electron beam irradiation. Sample structures before and after electron beam irradiation are recorded by high resolution imaging and coherent nano-area electron diffraction using transmission electron microscopy (TEM). The atomic pair distribution functions of the sample are obtained from electron diffraction patterns. In the quasi-2-dimensional amorphous carbon material, the carbon hexagonal ring structure is not the main structural feature anymore, and the low order nearest distances between carbon atoms are slightly different from that in perfect graphene. Although the sample shows a long-range disordered atomic arrangement, it still holds short-range order and even middle-range order extending to 0.5 nm, as many zigzag carbon chains remain after electron beam irradiation.
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