engleski

Low-temperature Raman spectra of 2-adamantanone in different phases

The experimental results that show the existence of different low-temperature phases of 2-adamantanone (glassy crystal state, ordered crystal state and amorphous state in the form of molecular film) are presented. The glassy crystal state is obtained by rapid cooling of the room-temperature plastic phase. The freezing involves primarily the molecular rotational degrees of freedom while the translational order of the plastic phase is preserved. The phase transition to the ordered crystal state can be induced by very slow annealing between the room temperature and 10 K. Amorphous 2-adamantanone films were prepared by vacuum evaporation and deposition onto cold metal substrate at temperature 10 K. The obtained low-temperature structures of 2-adamantanone exhibit substantially different low-frequency Raman spectra (100 - 10 cm-1) when analysed by means of reduced Raman intensity.

2-adamantanone ; glassy crystal ; ordered crystal ; amorphous film

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