钾对云母(001)上的 para-六苯薄膜生长的影响。

The influence of potassium on the growth of ultra-thin films of para-hexaphenyl on muscovite mica(001).

机构信息

Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria.

出版信息

J Chem Phys. 2012 Oct 7;137(13):134701. doi: 10.1063/1.4754833.

Abstract

The interaction of potassium with mica(001) and its influence on the subsequent film growth of para-hexaphenyl (6P) was studied by Auger electron spectroscopy, thermal desorption spectroscopy, and atomic force microscopy (AFM). Freshly cleaved mica is covered with 0.5 monolayer (ML) of potassium. By intentional potassium deposition in ultra-high vacuum a saturation of 1 ML can be achieved, which is stable up to 1000 K. Additional potassium desorbs at around 350 K. The film morphology of 6P on mica(001) is significantly influenced by the potassium monolayer. On the freshly cleaved mica surface, which contains 1/2 ML of K, 6P forms needle-like islands which are composed of lying molecules. On the fully potassium covered mica surface 6P grows in form of dendritic islands, composed of standing molecules. The reason for this change is attributed to the removal of lateral electric fields which exist on the freshly cleaved mica surface, due to the specific arrangements of the atoms in the surface near region of mica.

摘要

钾与云母（001）的相互作用及其对随后的对-六苯并菲（6P）薄膜生长的影响通过俄歇电子能谱、热脱附光谱和原子力显微镜（AFM）进行了研究。新鲜劈开的云母表面覆盖有 0.5 单层（ML）的钾。通过在超高真空下有意沉积钾，可以达到 1 ML 的饱和，在 1000 K 以下稳定。在大约 350 K 时，额外的钾会脱附。6P 在云母（001）上的薄膜形态受到钾单层的显著影响。在含有 1/2 ML K 的新鲜劈开的云母表面上，6P 形成由躺式分子组成的针状岛。在完全被钾覆盖的云母表面上，6P 以由直立分子组成的枝状岛的形式生长。这种变化的原因归因于由于云母表面近区原子的特定排列，存在于新鲜劈开的云母表面上的横向电场的消除。