Anomalously high-density glass of ethylbenzene prepared by vapor deposition at temperatures close to the glass-transition temperature

Molar volume Vm of ethylbenzene glass vapor-deposited on a metal substrate was studied as a function of deposition temperature Td. Initial Vm of deposited sample showed a minimum at Td around 0.86–0.91 times the glass-transition temperature Tg. Glass deposited at these or higher Td close to Tg had Vm smaller than that estimated for supercooled liquid at the same temperature. Such dense glass showed relaxation accompanied with volume expansion at temperatures slightly higher than Tg. These observations are in harmony with those by Ediger and coworkers [S.F. Swallen et al., Science 315 (2007) 353] for vapor-deposited glass made of much larger molecules.