Mechanical Properties of Various Phases on In/Si(111) Surfaces Revealed by Atomic Force Microscopy

Abstract

In/Si(111) surfaces have a variety of phases, among which 4×1 and √7×√3 show intriguing one-/two-dimensional (1D/2D) electronic properties. Here, we carry out extensive experiments to investigate the mechanical properties of various phases on the surfaces by atomic force microscopy at room temperature. Energy dissipation associated with flexibility is measured at the atomic scale. In the 4×1 phase, dissipation locally increases at the inner parts of couples of In chains, which correspond to mobile In atoms in a dynamical fluctuation model for the phase transition. An extremely large dissipation signal is obtained on the √7×√3 phase, indicating that a single atomic layer of In is weakly attached to the Si substrate, which is consistent with the 2D electronic properties.