Surface Melting and Surface Roughening

本提案描述了一系列旨在解决晶体表面在高温下稳定性问题的实验。在金属相对开放的表面上，三种不稳定性的关系特别有趣；表面粗化、表面熔化和不可逆的表面重建。金属表面是研究这三种不稳定性的特殊候选者，因为这些不同结构转变的温度（无论是已经测量的还是理论上预测的）都非常相似。所有这些研究都需要关于长期相关性对温度依赖性的详细信息。这一信息将通过低能电子衍射谱的精确测量获得。了解金属表面的粗化将是非常有趣的，因为在粗化温度以上存在高浓度的活性吸附位点对许多重要的催化过程至关重要。此外，表面粗化和表面熔化现在被认为是半导体超晶格和金属-半导体界面生长的重要因素。

This proposal describes a series of experiments aimed at addressing the questions of the stability of crystal surfaces at elevated temperatures. The relationship of three types of instabilities on the relatively open surfaces of metals are particularly interesting; surface roughening, surface melting, and irreversible surface reconstructions. Metal surfaces are exceptional candidates to study all three instabilities since the temperatures for these different structural transformations (whether already measured or theoretically predicted) are all very similar for this face. All of these studies require detailed information on the temperature dependence of the long range correlations. This information will be obtained through accurate measurements of low energy electron diffraction profiles. Understanding roughening on metal surfaces will be of extreme interest since the high concentration of active adsorption sites present above the roughening temperature are critical to many important catalytic processes. In addition, surface roughening and surface melting are now recognized as important factors in the growth of semiconductor superlattices and metal-semiconductor interfaces.