Investigation of broken symmetry of Sb/Cu(111) surface alloys by VT-STM

Abstract

This work present an in situ Variable Temperature Scanning Tunneling Microscopy (VT-STM) study of the Sb/Cu(111) system studied at various temperatures. The experimental data support a structural model in which Sb atoms displace up to 1/3 of the first layer of Cu atoms and incorporate them into the first Cu layer. In contrast to the clean Cu(111) substrate the surface of the surface alloy is corrugated due to the outward relaxation of the alloy atoms thus breaking the surface structural symmetry. The study report for the first time to our knowledge the observation of the Cu(111)(2 x 2) -Sb superstructure obtained at elevated temperatures.