title: Fast Crystal Growth Induces Mobility and Tension in Supercooled o-Terphenyl.
abstract: A photobleaching method was used to measure the reorientation of dilute probes in liquid o-terphenyl near a crystal growth front. Near the glass-transition temperature Tg, mobility in the supercooled liquid was enhanced within ∼10 μm of the crystal growth front, by as much as a factor of 4. This enhanced mobility appears to be caused by tension created in the sample as a result of the density difference between the supercooled liquid and crystal. The maximum observed mobility enhancement corresponds to a tension of about -8 MPa, close to the cavitation limit for liquid o-terphenyl. Whereas the observed mobility near the growing crystal is not large enough to explain the extraordinary fast crystal growth observed near Tg in o-terphenyl and some other low-molecular-weight glassformers, these observations suggest that cavitation or fracture plays a key role in releasing tension and allowing fast crystal growth to occur at a steady rate.
authors: †Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
authors: Keewook
authors: K
authors: Paeng
authors: †Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.|‡School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.
authors: C Travis
authors: CT
authors: Powell
authors: †Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.|‡School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States.
authors: Lian
authors: L
authors: Yu
authors: †Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
authors: M D
authors: MD
authors: Ediger
keywords: GC crystal; molecular mobility; organic glassformers; rotational diffusion