Applied Surface Science, Vol.446, 196-200, 2018
Structure transformations in thin films of CF3-CFH2 cryodeposites. Is there a glass transition and what is the value of T-g?
In the temperature range 16-100 K, IR spectrometric studies of thermally stimulated transformations in cryocondensed Freon 134a films were carried out. It was found that Freon 134a cryofilms, formed at T = 16 K, under heating range from 70 to 90 K undergo multiple structural transformations of various nature. It was concluded that at a temperature of T-g = 72 K, takes place the glassy state transition to the supercooled liquid (G-SCL). At about T = 78 K, crystallization of SCL begins the state of an orientationally disordered plastic crystal. At a transition temperature T-trans = 80 K, a second quasi-glass transition occurs from the state of the orientation glass to a plastic crystal with an ordered rotational subsystem. Within temperature range 83-85 K, a plastic crystal-monoclinic crystal phase transition takes place. (C) 2018 Elsevier B.V. All rights reserved.