Angular Distribution of Sublimed and Sputtered Particles from Ag Single Crystals

Abstract

When silver (100) and (110) single crystals were sputtered by 160–200-eV argon ions from an arc the well-known spot patterns appeared when the sputtered particles were collected as a thin film on glass plates. To determine whether similar spot patterns would result from sublimation, the same crystals were sublimed at temperatures between 642° and 815°C under high-vacuum conditions. Optical transmission densitometer measurements on the resulting thin films indicated that during sublimation the emission was approximately cosine, and no evidence of preferential ejection of silver particles during sublimation was detected. It is estimated that if preferential ejection is taking place along the close-packed directions of the crystal during sublimation in this temperature range, this emission produced a thickness change of the collected silver films such that the transmitted light intensity varied from a cosinelike curve by less than 5% at those angles.