Anisotropic growth of Cr Ad-layer: a one-dimensional nanostructure
The growth behavior of Cr ad-layer on W(110) surface was studied with scanning tunneling microscopy. Two-dimensional islands are formed at Cr coverage of ∼0.3 monolayer, suggesting typical homogeneous nucleation. The growth mode undergoes a transition to the formation of organized nano-scale lines at the coverage of >0.5 monolayer. The grown lines are aligned along [-111] and [1-11] directions at room temperature. At an elevated temperature, trenches are formed in a two-dimensional wetting layer with high aspect ratios. Possible microscopic origins for the observed structures are discussed.