Asymmetric crystal topography of diacetylene and polydiacetylene macroscopic single crystals

Abstract
X-ray transmission asymmetric crystal topography was used to investigate the changes in defect structure which occur during the solid-state polymerization of macroscopic single crystals of a diacetylene. Comparison of x-ray topographs made before and after gamma-ray-induced polymerization indicate that lattice strain increases during polymerization, but important defect structures present in monomer crystals are retained in the polymer crystals. A cross-pattern defect structure along 〈201〉 crystallographic directions is typically observed in both monomer and polymer single crystals.