Zhang Jie, He Yunteng, Freund William M, Kong Wei
Department of Chemistry, Oregon State University , Corvallis, Oregon 97331, United States.
J Phys Chem Lett. 2014 Jun 5;5(11):1801-1805. doi: 10.1021/jz5006829. Epub 2014 May 7.
We present experimental results of electron diffraction of superfluid helium droplets and droplets doped with phthalocyanine gallium chloride and discuss the possibility of performing the same experiment with a laser aligned sample. The diffraction profile of pure droplets demonstrates dependence on the nozzle temperature, that is, on the average size of the droplets. Larger clusters demonstrate faster decay with increasing momentum transfer, whereas smaller clusters converge to isolated gas phase molecules at source temperatures of 18 K and higher. Electron diffraction of doped droplets shows similar modified molecular scattering intensity as that of the corresponding gas phase molecules. On the basis of fittings of the scattering profile, the number of remaining helium atoms of the doped droplets is estimated to be on the order of hundreds. This result offers guidance in assessing the possibility of electron diffraction from laser aligned molecules doped in superfluid helium droplets.
我们展示了超流氦滴以及掺杂有氯化镓酞菁的氦滴的电子衍射实验结果，并讨论了使用激光排列样品进行相同实验的可能性。纯氦滴的衍射图谱表明其依赖于喷嘴温度，也就是依赖于液滴的平均尺寸。较大的团簇随着动量转移的增加呈现出更快的衰减，而较小的团簇在18K及更高的源温度下会汇聚到孤立的气相分子。掺杂液滴的电子衍射显示出与相应气相分子类似的修正分子散射强度。基于散射图谱的拟合，估计掺杂液滴中剩余氦原子的数量在数百量级。这一结果为评估超流氦滴中掺杂的激光排列分子的电子衍射可能性提供了指导。
