Solid–solid phase transitions in n-alkanes C23H48 and C25H52: X-ray power diffraction study on new layer stacking in phase V

Publisher Website
Google Scholar
Abstract
The solid–solidphase transitions and the crystal structures of odd n‐alkanes, n‐C23H48, and n‐C25H52, were investigated by x‐ray powder diffraction. The phase transitions, I→V→RI for n‐C23H48 and I→V→IV→RI for n‐C25H52, were observed, where phases I, V, IV are the low‐temperature ordered phases, and the phase RI is the rotator phase. The crystal structure of phase V was determined by the Rietveld profile refinement method. Phase V is orthorhombic (P bnm ). New molecular layer stacking appears in phase V, while the lamellar structure and the lateral packing of molecules are same as those in phase I and phase IV. The solid–solidphase transitions below the rotator phase transition of odd n‐alkanes found to be characterized by the changes in molecular layer stacking are considered to be caused by the increased disorder in the layer surface.

This publication has 19 references indexed in Scilit: