Behaviour of discontinuous gold films on SrTiO3 substrates under annealing

Morphological changes of thin, discontinuous gold films on SrTiO3 substrates, resulting from evaporation in the temperature range of 1143-1278 K, have been investigated by means of scanning electron microscopy (SEM) and atomic force microscopy (AFM). If the gold covered fraction of the surface is small, the evaporation kinetics can be related to the desorption of adatoms. Measuring the density of the gold beads and the time dependence of the effective thickness of the film as calculated from the diameter of the beads, the following parameters have been determined: the surface diffusion length of the gold adatoms, λs(m)=(2.2−2.0+26.7)×10−3×exp[−(77±26)kJ/mol/RT], the mass transfer surface diffusion coefficient, D′s(m2/s)=(3.25−3.23+433)×1010×exp[−(560±49)kJ/mol/RT] and the evaporation flux, J(m−2s−1)(2.79−2.76+267)×1035×exp[−(426±46)kJ/mol/RT].