Structure transformations in thin films of CF3-CFH2 cryodeposites. Is there a glass transition and what is the value of Tg?

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. [ABSTRACT FROM AUTHOR]