Epitaxy and twinning in foils of some noble metals condensed upon lithium fluoride and mica

Foils up to 2.5 × 10-3 cm in thickness, of Cu, Ag, Pd and Au, have been evaporated on to LiF and mica crystals, epitaxial growth was observed within fixed temperature ranges for each substrate-metal combination. X-ray diffraction of the foils produced sharp patterns of spots which indicated a principal orientation of crystallites in direct alignment with the substrate crystal, together with twins whose presence was confirmed by metallography. The observations are discussed in terms of a nucleation and growth model.