Single-Crystal Tin Films

Abstract

High‐purity tin films have been made in ultrahigh vacuum by evaporation on (001) faces of NaCl at liquid nitrogen temperature and 0°C. An evaporation rate of approximately 50 A/sec was used. Film thicknesses ranged from 1000 to 3600 A. The films were allowed to warm to room temperature before they were removed from the vacuum system and examined by the techniques of electron diffraction and electron microscopy. Single‐crystal films were obtained when the substrates were at liquid nitrogen temperature and when cleaved surfaces and short successive evaporation times were used. If the substrates were at 0°C, or one continuous evaporation of more than about 10 sec was made, the resulting film was polycrystalline and (100) oriented. Grain growth in all the polycrystalline films could be produced by electron‐beam bombardment in the electron microscope. Some of the factors influencing grain growth are discussed.