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

Abstract

A systematic study of surface structures of 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 X 1), (2 X 1), (3 X 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 [110]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 X 2), (1 X 1), (4X 1), (5 X 1), and (n X 1) where n & 8 with an increase of Li coverage. The first (1 X 2) structure was assigned to a missing-row-type restructuring of the substrate Cu atoms. The structure models for the (4X 1), (5 X 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.

Adsorption of Li on Cu(110): Density-functional calculations

“…We also tested the adsorption energy of Li at high coverage, and found that the hol site was still the most preferred site. Our findings are in agreement with Nakanishi et al's investigation with the help of LEED and AES techniques [4]. For the adsorption of lbri sites at both coverages, the energies are found to be about 0.1 eV less stable than the hol sites.…”

“…It is indicated that the rumpling between the planes defined by atoms of Li and Cu in the 1st-layer has been formed. Using LEED, Nakanishi et al also proposed that surface alloys similar to those observed on Cu(0 0 1) surface were formed on the present Cu(1 1 0) surface [4]. They found that at low temperatures Li overlayers were formed on Cu surfaces, while at room temperature intermixed layers of Li and Cu were formed.…”

“…In order to explore the adsorption of Li at high coverage, guided by experiment [4], five phases for Li adsorption at the most favored site have been considered (shown in Fig. 2).…”

“…Recently, besides the phase of Cu(1 1 0)-(1 Â 2), Nakanishi et al observed a series of patterns, i.e., (2 Â 1), (3 Â 1), (4 Â 1), (5 Â 1), (6 Â 1) and (7 Â 1), with the help of LEED and Auger electron spectroscopy (AES) techniques [4]. From the investigation, they proposed that the surface alloys similar to those observed on Cu(0 0 1) were formed on the Cu(1 1 0) surface.…”

“…The adsorption of Li on Cu(1 1 0) surface has been widely investigated [1][2][3][4][5][6][7]. Many investigations have focused on the analysis of the Li-induced reconstructed Cu(1 1 0)-(1 Â 2) surface.…”