UNEXPECTED EFFECTS OF FORCED HIGH NUCLEATION DENSITIES BY FLASH EVAPORATION OF GOLD ON NaCl and KCl SUBSTRATES

Abstract

Gold was deposited slowly and simultaneously on air‐cleaved NaCl and vacuum‐cleaved NaCl and KCl crystals, portions of which had been covered with about 20 Å of gold by simultaneous flash deposition prior to the commencement of slow deposition 320°C substrate temperature. The epitaxy of gold on vacuum‐cleaved NaCl substrates is enhanced by the higher nucleation density resulting from the flash deposition while the latter causes a deterioration of the epitaxy on both vacuum‐cleaved KCl and air‐cleaved NaCl substrates. It is proved that no effective substrate contamination results from the flash evaporation. It is suggested that a critical or epitaxial nucleation density exists for each deposit‐substrate system.