The film temperature is usually not known and one often uses the substrate temperature; a
point that warrants closer examination and that will lead to a more general temperature
concept developed in the next section. Based on the analysis of many samples Movchan
and Demchishin concluded that three zones can be distinguished. In zone 1, at 0.3 h T < , the adatom mobility is low leading to continued nucleation of grains. This results in a
fine-grained structure of textured and fibrous grains, pointing in the direction of the