X-ray Damage to CF3CO2-Terminated Organic Monolayers on Si/Au: Principal Effect of Electrons
X-ray Damage to CF3CO2-Terminated Organic Monolayers on Si/Au: Principal Effect of Electrons
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Si/Au 上 CF3CO2 封端的有机单层的 X 射线损伤：电子的主效应
DOI：
10.1126/science.254.5034.981
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发表时间：
1991
期刊：
影响因子：
56.9
通讯作者：
G. Whitesides
中科院分区：
文献类型：
--
作者：
P. E. Laibinis;R. Graham;H. Biebuyck;G. Whitesides
通过在多层薄膜支撑上使用自组装单层 (SAM)，探索了单独的 X 射线以及 X 射线产生的一次和二次电子在破坏有机材料中的相对重要性。通过在厚金层（2000 埃）上沉积硅薄膜（0、50、100 和 200 埃）来制备基板。这些系统由镀铬硅片支撑。将三氟乙酰氧基封端的 SAM 组装在这些基底上，并用普通的单色铝 Kα X 射线辐照样品。然而，X 射线与各种基底相互作用所产生的电子的通量和能量分布是不同的。发射电子通量较低的基板表现出 SAM 中氟的损失较慢。这一观察结果表明，电子（而不是 X 射线本身）对有机单层的损坏负有主要责任。
The relative importance of x-rays alone and of x-ray-generated primary and secondary electrons in damaging organic materials was explored by use of self-assembled monolayers (SAMs) on multilayer thin-film supports. The substrates were prepared by the deposit of thin films of silicon (0, 50, 100, and 200 angstroms) on thick layers of gold (2000 angstroms). These systems were supported on chromium-primed silicon wafers. Trifluoroacetoxy-terminated SAMs were assembled on these substrates, and the samples were irradiated with common fluxes of monochromatic aluminum Kα x-rays. The fluxes and energy distributions of the electrons generated by interactions of the x-rays with the various substrates, however, differed. The substrates that emitted a lower flux of electrons exhibited a slower loss of fluorine from the SAMs. This observation indicated that the electrons—and not the x-rays themselves—were largely responsible for the damage to the organic monolayer.