X-ray Diffraction and Polymorphism of Smectic Liquid Crystals 1. A-, B- and C-modifications

Abstract

Abstract X-ray diffraction patterns of 14 substances have been studied in non-oriented samples in the smectic modification sA, sC, and sB. In all three modifications a sharp reflexion was found at small angles. At large angles a diffuse reflexion was found in the modifications sA and sC, and a sharp reflexion in the modification sB. In all cases the calculated layer separation d is smaller than the molecular length L in the most stretched molecular structure. The X-ray patterns obtained from oriented samples of two substances are described and compared with the results obtained by other investigators. Further the results of the investigation of the equatorial intensity distribution are described.