ADSORPTION AND REACTION OF NITRIC OXIDE ON Si(111)-Au SURFACES

We studied adsorption and reaction of nitric oxide on Si(111)7 × 7, 5 × 2-Au, $\alpha-\sqrt{3},\times \sqrt{3}-{\rm Au}$, $\beta-\sqrt{3} \times \sqrt{3}-{\rm Au}$, and 6 × 6-Au surfaces with low-energy electron diffraction, Auger electron spectroscopy, and scanning tunneling microscopy (STM). We found that NO gas reacts most strongly with the 7 × 7 surface, strongly with the 5 × 2-Au surface, and little with the other Si(111)-Au surfaces. STM results indicated that the NO exposure removes adatoms and erodes the row structure on the 5 × 2-Au surface at room temperature.