Auger/LEED Investigation of the Deposition of Al Onto the Mo(110) Surface

Six different structures and one amorphous phase are formed by Al on the Mo(110) surface. Three of the six structures are of two orientations along the Mo [1, 1], [2, 1] and [1, 1], [1, 1] directions giving LEED patterns rotated ± 35°16' from the [o, k ] direction. The Al/Mo mismatch causes the growth of a stressed Al(111) surface as evidenced by a streaked LEED pattern, but an ideal Al(111) surface can be achieved with a thick deposition. The diffuse phase of Al coverage forms only from the ideal Al(111) structure. The c(2 × 2) structure forms from every initial structure upon heating to a high temperature (except for the 1–3 min depositions) and gives way to the low-coverage Al structure at a higher temperature. CO contamination from pressure > 10−8 torr during Al deposition inhibits formation of Al structures during short (1–3 min) depositions.