Study of the nature of glass transitions in the plastic crystalline phases of cyclo-octanol, cycloheptanol, cyanoadamantane and cis-1,2-dimethylcyclohexane

Abstract

Structural signature of the configurational entropy change during the glass formation of plastic crystal cyanoadamantane

Solid phases in cycloheptanol: Dynamic disorder and glass transitions

“…In addition, the X-ray diffraction profile, recorded again at 213 K on heating mode, is similar to that obtained from the annealing process making clear the stability of phase III. The observed behavior could be compatible with the existence of another phase, denoted as phase IV, at temperatures lower than 170-180 K. The existence of this phase IV would be in accord with the earlier works of Tyagi et al [20] and Adachi et al [22]. All attempts to determine unambiguously the new symmetry corresponding to phase IV were unsuccessful, probably for lack of an adequate number of unambiguous reflections.…”

“…There exists a wide consensus in the scientific literature about three stable solid phases, although, some evidences for an additional stable solid phase have been reported [20,22]. The first two solid phases (phases I and II) appearing on cooling the liquid state are undoubtedly OD-states [20,21,23] and they can be supercooled, phase I much more easily than phase II, giving rise to two different OG-states. It is clear that C 7 -OH is a double OGforming material, but the question that arises now is, could the C 7 -OH be considered as a CG-forming material such as its homologue C 8 -OH?…”

“…As for its solid state polymorphism, a great amount of works has been published up to now, in which several experimental techniques have been used [20][21][22][23][24][25][26][27]. Surprisingly, next to nothing devoted to the structural features of the solid states has been published [27].…”

“…Surprisingly, next to nothing devoted to the structural features of the solid states has been published [27]. There exists a wide consensus in the scientific literature about three stable solid phases, although, some evidences for an additional stable solid phase have been reported [20,22]. The first two solid phases (phases I and II) appearing on cooling the liquid state are undoubtedly OD-states [20,21,23] and they can be supercooled, phase I much more easily than phase II, giving rise to two different OG-states.…”

Dynamics of orientationally disordered mixed crystal sharing Cl-adamantane and CN-adamantane

“…CN-A has been studied by means of an extended number of experimental techniques [13,[17][18][19][20][21][22][23][24][25][26][27]. As far as its polymorphism is concerned, the low-temperature ordered phase is monoclinic (space group C2/m, Z = 4).…”