The change of the lattice constant in heteroepitaxial silver films with increase of thickness

Deposition of silver on NaCl, KCl, and LiF with 20 Å · s⁻¹ in vacuum (5 · 10⁻⁶ torr) and electronographical determination of changes of lattice constant. Precision of measurement better than ± 0.004 Å (reflections {400} and {220}). Thickness of films from 50 to 500 Å with intervals of 10 Å. The lattice parameter of films till to 115 Å in thickness did'nt differ from the parameter of bulk silver (4.086 Å). At about 175 Å the parameter reached minimum (about 4.00 Å) and took again the parameter of bulk material with the film thickness of 215 Å. With polycrystals no changes of lattice parameters occurred. – The phenomenon is connected to growth mechanism, two-dimensional and three-dimensional nucleation and to the differences in lattice parameters of substrate and deposit.