Ripple Structure on Ag(110) Surface Induced by Ion Sputtering

The morphology of the Ag(110) surface after ${\mathrm{Ar}}^{+}$ ion sputtering has been studied by a variable temperature scanning tunneling microscope. For ion energies greater than 800 eV and in the temperature range $270<\mathrm{}{T}_S<320\mathrm{}\mathrm{K}$ (where $T_S$ is the sputtering temperature), a peculiar ripple structure well aligned along the $〈1\overline{1}0〉$ direction and independent of the ion beam angle has been observed. A simple model of this effect, based on the anisotropy and on the temperature hierarchy of the Ag adatom and vacancy surface diffusion, explains the observed features.