Morphology and structure of ZnS grown from vapour phase

Abstract ZnS crystals were grown from the vapour phase in a sealed vessel with a temperature gradient. The growth behaviour was observed in situ and the growth rate was measured. The crystal structure was examined by optical observations and X-ray diffraction at room temperature. Below the transition temperature T c (= 1024°C) the crystals were mostly of stubby and block forms with cubic structure, when the crystal were grown from the source of relatively large crystals. On the other hand, when powder was used as the source crystals, branched crystals with hexagonal structure were grown. If the hexagonal crystals were used as seed, the structure of regrown crystals was always hexagonal. Above T c , generally, crystals with branches were obtained. On the seeds grown below T c , however, the crystals of stubby and block shapes were grown from the source of relatively large crystals. The crystal structure was always hexagonal. The polytype structures were found only in the crystals grown above 1120°C.