MICROSTRUCTURE OF VACUUM-DEPOSITED THIN SILVER BROMIDE LAYERS

The microstructure - average size and size dispersity - of the microcrystalites building up AgBr layers is investigated as a function of the deposition rates in the range of 40-950 Angstrom/s on linearly moving substrates and in the range of 20-60 Angstrom/s on static ones. Unexpected results suggesting an independence of the microcrystallite average size on these deposition rates are obtained. It is supposed that at high supersaturations a threshold value of the deposition rate exists, beyond which the average size remains practically unaffected. It is established that this threshold value amounts to 20 Angstrom/s upon deposition on static substrates and that it is below or equal to 40 Angstrom/s in the case of linearly moving ones. Following the theory, the results obtained at the same deposition rate are interpreted assuming that the influence of the kinetic parameters on the average size of the microcrystallites prevails on the thermodynamic ones under the specific conditions of nucleation and crystal growth.