M. Hammar et al., INITIAL GROWTH OF SILVER ON GE(111) STUDIED BY SCANNING-TUNNELING-MICROSCOPY, Physical review. B, Condensed matter, 47(23), 1993, pp. 15669-15674
Scanning tunneling microscopy (STM) has been used to study the Ge(111)
surface after submonolayer depositions of Ag. At the lowest coverages
a (4 X 4) reconstruction, with small insets of a (3 X 1) edge structu
re, is observed. Based on the STM images we propose a mixed Ag and Ge
adatom structure for the (4 X 4) reconstruction, in which the adatoms
have local (1 X 1) and (2 X 2) arrangements corresponding to a Ag cove
rage of 6/16 monolayers. The (3 X 1) structure appears to have a confi
guration similar to the Si(111)/Ag-(3 X 1) reconstruction, although in
this case it has a much more limited extension, restricted to a few u
nit cells in the near vicinity of step edges and phase boundaries. At
higher coverages, after the completion of a full (4 X 4)/(3 X 1) surfa
ce, a (square-root 3 X square-root 3)R 30-degrees structure appears sh
owing STM images similar to those previously published for the Si(111)
/Ag system.