以鍺(111)及鍺(100)為基底之鉛薄膜熱穩定度比較

Comparison of Thermal Stability Between Pb Films on Ge(111) and on Ge(100)

梁立言(Li-Yen Liang)

指導教授 ： 唐述中

國立清華大學/理學院/物理學系/碩士(2011年)

https://doi.org/10.6843/NTHU.2011.00373

摘要

薄膜的許多性質受到薄膜內的量子尺度效應(Quantum Size Effect)所影響。而鉛薄膜的熱穩定度會隨著薄膜厚度增加而以2層薄膜為週期震盪，並伴隨著周期為9層薄膜的拍(beating)。此震盪及拍現象受到於薄膜中的量子井態在薄膜表面及薄膜與基底的界面的相位差的影響而使熱穩定度震盪中穩定層與不穩定層的層數產生平移或是拍的反轉點位置的整體平移(週期仍為9層)。我們以鍺(100)為基底並使鉛能在上形成二維平坦的整數層鉛薄膜。透過角解析光電子能譜(Angle-Resolved Photoemission Spectroscopy, ARPES)我們能得到不同厚度的鉛薄膜的瓦解溫度，即薄膜的熱穩定度，實驗結果則以Friedel 震盪(Friedel Oscillation)的物理模型擬合。最後將我們的結果與鉛/鍺(111)系統的鉛薄膜熱穩定度作比較，以研究不同基底對於鉛薄膜熱穩定度的影響。

關鍵字

角解析光電子能譜 ； 鉛 ； 鍺

並列摘要

The properties of thin films are controlled by the Quantum Size Effect in the films. For Pb films, the thickness dependence of thermal stability temperature exhibits bilayer oscillation modulated by a 9 ML beating pattern. The oscillation and beating phenomena are influenced by the phase shift of Quantum Well States at the interfaces of the films. We prepared uniform 2D Pb films on Ge(100), which grow layer by layer. By Angle-Resolved Photoemission Spectroscopy(ARPES) we obtained the thickness dependence of thermal stability temperature of Pb films, and the results are fitted by a model based on Friedel oscillations .Finally, we made a systematical comparison between Pb/Ge(100) and Pb/Ge(111) for the thermal stability to study the influence from the substrate.

並列關鍵字

ARPES ； Pb ； Cu

參考文獻

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