Observations of coverage- and temperature-dependent surface structures formed upon Li deposition on Cu(110)

A systematic study of surface structures of Li-covered Cu(110) was performed by means of low-energy electron-diffraction (LEED) and Auger electron spectroscopy techniques. The experiments were carried out with increasing deposition of Li both at low temperature (90 K) and room temperature (300 K). At 90 K a series of LEED patterns, (3×1), (2×1), (3×1), and successive complicated structures were observed with increasing Li coverage. The sequence of the LEED patterns was interpreted as simple overlayer structures of Li in terms of a continuous increase of the packing density of deposited Li atoms sitting in the trough along the [11̄0] direction of the Cu(110) surface. Marked differences in the sequence of the LEED structures were observed for observations at 300 K; the sequence of the structures was (1×2), (1×1), (4×1), (5×1), and (n×1) where n<8 with an increase of Li coverage. The first (1×2) structure was assigned to a missing-row-type restructuring of the substrate Cu atoms. The structure models for the (4×1), (5×1), and so on were discussed in terms of the formation of Li-Cu surface alloys proposed previously by Tochihara and Mizuno for the Li/Cu(100) system.