Dynamic behavior of silver islands growing on GaAs (001)2x4 substrate

The growth of silver deposited on the GaAs(001)-(2x4) surface has been investigated via scanning tunneling microscopy (STM). Silver aggregates in the Volmer-Weber mode, forming hut-shaped islands whose average dimension increases according to the power law Theta(1/z), with z approximate to 1.5 and Theta being the number of silver atoms deposited at constant rate on the substrate. We found that 80% of the islands are elongated in the [110] direction and bounded by {310} facets, while the remaining 20% are elongated in the [(1) over bar 10] direction and bounded by {210} facets.