ISSN:
1089-7690
Quelle:
AIP Digital Archive
Thema:
Physik
,
Chemie und Pharmazie
Notizen:
The solid–solid phase 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 (Pbnm). 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–solid phase 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. © 1995 American Institute of Physics.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.470456
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