INFLUENCE OF AG ADSORBATE ON THE SI(111)-ROOT-3X-ROOT-3-(AU,CU) STRUCTURE

The interaction of Ag adsorbate and the Si(111)-root 3 x root 3-(Au, C u) surface has been studied by means of LEED-AES-RBS techniques. A Ag film deposited onto the Si(111)-root 3 x root 3-(Au, Cu) surface at RT is examined by isochronal annealing at several temperatures. The Ag/S i(111)-root 3 x root 3-(Au, Cu) surface shows a clear 2 root 3 x 2 roo t 3 LEED pattern on annealing at 250 degrees C. The 2 root 3 x 2 root 3 LEED pattern persists instead of root 21 x root 21 or root 3 x root 3, even when the Ag coverage decreases to 0.3 ML. These results sugges t that the 2 root 3 x 2 root 3-(Au, Ag, Cu) structure has been newly p roduced for the first time in this experiment.