BARIUM FILMS ON MOLYBDENUM(110) - LEED AND EELS STUDY

Surface structure, work function changes and plasma losses have been s tudied for barium films on a Mo(110) surface. At 77 K in the (0.5-0.7) x 10(14) cm(-2) coverage range, Ba is in a two-dimensional liquid sta te. Film crystallization leads to the formation of a two-dimensional h exagonal structure with a density of (0.8-1.0)x 10(14) cm(-2). After a set of coherent structures at a coverage of (1.2-3.6)x 10(14) cm(-2) the hexagonal structure appears once again. Further Ba deposition occu rs within the framework of a monolayer-by-monolayer growth mode. Thr a ppearance of the Ba surface plasmon line (2.6 eV) in electron energy l oss spectroscopy concurs with the minimum in work function and the cov erage location of this appearance shifts as temperature changes. The B a bulk plasmon loss (6.7 eV) appears when condensation in the second l ayer begins. 1998 Elsevier Science B.V. All rights reserved.