Proton Decoration of Halite Crystals

Abstract

The decoration of glide bands and other features of halite crystals (NaCl) has been shown to result from proton irradiation at temperatures in the range 150-220°C. Optical transmission measurements before, during and after irradiation give very similar res'ults to those reported from studies of colour centres in synthetic NaCI. However, decoration is found to depend on the sequence of irradiation, exposure to light and the duration of sample heating. Both normal and colour-reversed bands have been observed for conditions leading to a final colour ranging from yellow/brown through blueto red/violet.