Scaling law and dynamical exponent in the Volmer–Weber growth mode: silver on GaAs(001)2×4

The growth of Ag deposited onto the GaAs(001)2×4 has been investigated by means of scanning tunnelling microscopy. Silver forms islands (Volmer–Weber growth) whose average dimension increases according to Θ1/z (with z=4.2), Θ being the number of Ag atoms deposited at constant rate onto GaAs. The Ag islands exhibit a hut shape with {210} and {310} facets. The kinetic of surface coverage has been measured and the Avrami exponent, n, has been determined, finding n=0.61. Both z and n are related to the dynamic nature of the growth process.