Sputter-erosion dynamics of Ni(110) surface

We have studied the morphological evolution of Ni(110) surface induced by l ow-energy ion sputtering at room temperature with scanning tunneling micros copy. We found that there are two different time regimes in the sputtering processes. In the first regime, a ripple structure is formed with the wave vector along the direction [110] due to the strong diffusion bias along the direction and the surface roughness increases fast with time. However, in the second regime, three-dimensional mounds are formed with absent anisotro py and the logarithmic surface roughness becomes saturated. (C) 2001 Elsevi er Science B.V. All rights reserved.