Mesoscopic description of the glacial state in triphenyl phosphite from anx-ray diffraction experiment

We present an x-ray-diffraction study performed in the different states of the molecular glass-forming liquid triphenyl phosphite (TPP). Investigation s carried out in the apparently amorphous state, the so-called "glacial" st ate, formed from isothermal aging at different temperatures in the range [2 10 K, 222 K], confirm previous findings about the structural description of the glacial state in terms of nanocrystallized domains. The very close rel ationship between the diffraction patterns of the glacial and crystalline s tates reveals that the glaciation corresponds to an aborted crystallization process. By fitting the whole diffraction pattern of the crystalline phase , all the Bragg peaks can be indexed in a monoclinic unit cell. From this i ndexation, a structural organization of glacial TPP is given and the domain size can be evaluated for different aging temperatures.