Crystallization and glass transition of chlorobenzene/toluene binary amorphous systems

Crystallization and glass-transition phenomena were studied for amorphous chlorobenzene (CB)/toluene (TL) binary systems as the function of composition. Samples were prepared by vapor-deposition onto cold substrates, and their structural changes due to temperature elevation were monitored with Raman scattering and light transmission. It was found that the crystallization temperature (T-c) of CB-rich amorphous samples increases as the TL concentration is increased. This is similar to the linear dependence of glass-transition temperatures (T-g) of many organic compounds on the concentration of additive. Also found was that T-c of TL-rich supercooled-liquids decrease as the CB concentration is increased. Issues related to the two kinds of T-c are discussed briefly.