Morphology and rotation twin of CuCl and CuBr crystals

Abstract

CuCl and CuBr crystals grown from the vapor phase are dendrites with the zinc-blende structure. Their growth direction is the 〈112〉 or the 〈110〉 direction. The {111} surfaces are polar surfaces framed by the {112} planes. Triangular etch pits appearr only on one side of the polar surfaces with concentrated HCl. From the etching behavior and X-ray studies, it was found that these crystals contain 60° rotation twins.