Femtosecond Near-Infrared Laser Desorption of Multilayer Benzene on Pt{111} :A Molecular Newton's Cradle? †
Femtosecond Near-Infrared Laser Desorption of Multilayer Benzene on Pt{111} :A Molecular Newton's Cradle? †
复制标题
Pt{111} 上多层苯的飞秒近红外激光解吸：分子牛顿摇篮？
DOI：
10.1021/jp993688e
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发表时间：
2000
影响因子：
3.3
通讯作者：
D. King
中科院分区：
文献类型：
--
作者：
H. Arnolds;C. Rehbein;G. Roberts;R. Levis;D. King
报道了强激光、近红外激光脱附吸附在铂{111}上的多层苯的速度分布是激光强度的函数，激光强度随剂量和脉宽的变化而变化。速度分布随强度的变化呈现出热诱导脱附和电子诱导脱附的特征。将脉冲宽度从亚皮秒改变为亚纳秒，速度分布只有很小的定量变化，表明激光脉冲宽度跨度为3个数量级时，存在类似的脱附机制。讨论了可能的机理，并提出了一种新的机理，即该过程是由化学吸附层中的热辅助饮食激发启动的，随后通过分子牛顿摇篮机制将能量从铂−苯界面转移到最外层的苯层。
Velocity distributions resulting from the intense, near-IR laser desorption of multilayers of benzene adsorbed on Pt{111} are reported as a function of laser intensity, which was varied by changing fluence and pulse width. The velocity distributions as a function of intensity show characteristics of both thermally and electronically induced desorption. Changing the pulse width from the subpicosecond to the subnanosecond regime only results in a small quantitative change in the velocity distributions, suggesting a similar desorption mechanism for laser pulse duration spanning 3 orders of magnitude. Possible mechanisms are discussed and a new mechanism is proposed in which the process is initiated by a thermally assisted DIET excitation in the chemisorbed layer, and followed by energy transfer from the Pt−benzene interface to the outermost benzene layers via a molecular Newton's cradle mechanism.