Structural relaxation as a forked road to crystallization and glass transition of vapor-deposited amorphous molecular systems

Structural changes of chlorobenzene/toluene and chlorobenzene/ethylbenzene binary amorphous systems due to temperature elevation were studied with Raman scattering, X-ray diffraction, and light-transmission monitoring for samples prepared by vapor deposition on cold substrates. Two distinct behaviors of the samples, namely direct crystallization and glass transition, were observed depending on the composition of the sample. Structural relaxation which the system steps into in advance of crystallization or glass transition is pointed out to be a forked road that leads vapor-deposited amorphous molecular systems to these two kinds of structural changes. (C) 2004 Elsevier B.V. All rights reserved.