Electron-beam-induced fragmentation in ultrathin C 60 films on Si(100)-2×1-H: Mechanisms of cage destruction
Electron-beam-induced fragmentation in ultrathin C 60 films on Si(100)-2×1-H: Mechanisms of cage destruction
复制标题
Si(100)-2×1-H 上超薄 C 60 薄膜的电子束诱导碎裂：笼破坏机制
DOI：
10.1103/physrevb.60.5927
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发表时间：
1999
影响因子：
3.7
通讯作者：
R. Palmer
中科院分区：
文献类型：
--
作者：
M. Hunt;J. Schmidt;R. Palmer
我们证明了用3.3和0.5 keV电子束辐照生长在Si(100)−2× 1−H上的c60超薄（1 - 4单层）薄膜会导致富勒烯分子的大量修饰和最终破坏。碎片化的富勒烯在持续的电子照射下聚结，形成具有石墨局部结构的非晶材料。在使用的辐照条件下，没有观察到可测量的富勒烯或衍生碎片的解吸。当电子剂量低于使富勒烯发生完全破坏的电子剂量时，我们观察到有证据表明，由于分子的电子激发，富勒烯被入射电子束释放的氢原子氢化。对由较大电子剂量引起的可能碎裂机制的研究得出结论：电子激发衰变为分子的振动模式是最可能发生笼破坏的途径。
We demonstrate that irradiation of ultrathin (1–4 monolayer) films of C 60 grown on Si (100)− 2× 1− H with 3.3 and 0.5 keV electron beams leads to substantial modification of the fullerene molecules and their ultimate destruction. The fragmented fullerenes coalesce under continued electron irradiation to form an amorphous material with graphitic local structure. No measurable desorption of fullerene or derived fragments is observed under the irradiation conditions used. At electron doses below those at which complete fullerene destruction occurs we observe evidence indicating polymerization, due to electronic excitation of the molecules, and fullerene hydrogenation by atomic hydrogen liberated by the incident electron beam. An examination of possible fragmentation mechanisms resulting from larger electron doses leads to the conclusion that decay of electronic excitations into vibrational modes of the molecule is the most likely route through which cage destruction occurs.