Multiple glass transitions in vapor-deposited orientational glasses of the most fragile plastic crystal Freon 113

Abstract

We investigate by fast-scanning nanocalorimetry the formation of Freon 113 films from the vapor phase at deposition temperatures ranging from 50 to 120 K, that is, spanning above and below the transition temperature of the glassy crystal to the plastic crystal (T_gc = 72 K). Analysis of the heat capacity curves indicates that vapor deposition at T < T_gc of the highly fragile Freon 113 yields structural and orientational glasses in the as-deposited state depending on the temperature range of deposition. Interestingly, growing above T_gc produces plastic crystals with a conformational ratio C₁/C_s that changes with T_dep above and below 110–120 K, the temperature at which previous works have identified the arrest of the transformations between the C₁ and C_s conformers.