The growth of ultra thin Cu-films on Pt(111), probed by helium atom scattering and scanning tunnelling microscopy

The growth of ultra thin Cu films (up to 25 ML) on Pt(111) at a substrate temperature of 340 K has been investigated using helium atom scattering (HAS) and scanning tunneling microscopy (STM). In the first monolayer the growth is 2D-pseudomorphic with nucleation at step sites. No reconstruction of the substrate is observed. Diffusion limitation along the step edges leads to the formation of branched island structures which coalesce leaving randomly distributed holes (on average 30 A in diameter) as revealed by STM measurements.