Glass in a stretched state formed by negative-pressure vitrification: Trapping in and relaxing out

To explore the influence of the attractive side of the intermolecular potential on liquid structure and dynamics, we are studying liquids under negative pressure. To preserve and characterize the interesting stretched configurational states, we have vitrified the glass-forming liquid o-terphenyl under {~}80-bar negative pressure. The ambient pressure relaxation to normal volume at Tg of the stretched glass shows pronounced differences from the relaxation of the corresponding compressed state, suggestive of an increased ``fragility'' of liquids under tension.