Roughening of Au(111) Surfaces During Ion Beam Erosion: A Scanning Tunneling Microscope and X-Ray Diffraction Study

摘要

Using Scanning Tunneling Microscopy(STM) and X-ray diffraction(XRD) we have studied the development of surface roughness on Au(111) during 500eV Ar~+ ion irradiation at different angles. During normal incidence erosion the surface roughens and pattern formation occurs. The surface morphology is a mixture of mounds and pits superimposed onto a larger structure of channels and valleys. The characteristic spacing between features grows with a power law behavior t~(.27), where t is the amount of time the sample was irradiated, in agreement with previous measurements[1]. At glancing angles, erosion proceeds smoothly, but not in layer-by-layer fashion. Finally, a combination of glancing angle and normal incidence erosion is used to create a rippled morphology.