title: Fast crystal growth from organic glasses: comparison of o-terphenyl with its structural analogs.
abstract: Crystal growth kinetics and liquid dynamics of 1,2-diphenylcyclopentene (DPCP) and 1,2-diphenylcyclohexene (DPCH) were characterized by optical microscopy and dielectric spectroscopy. These two molecules are structurally homologous and dynamically similar to the well-studied glassformer ortho-terphenyl (OTP). In the supercooled liquid states of DPCP and DPCH, the kinetic component of crystal growth ukin has a power law relationship with the primary structural relaxation time τα, ukin [proportionality] τα(–ξ) (ξ ≈ 0.7), similar to OTP and other fragile liquids. Near the glass transition temperature (Tg), both DPCP and DPCH develop much faster crystal growth via the so-called GC (glass to crystal) mode, again similar to the behavior of OTP. We find that the α-relaxation process apparently controls the onset of GC growth, with GC growth possible only at sufficiently low fluidity. These results support the view that GC crystal growth can only occur in systems where the liquid and crystal exhibit similar local packing arrangements.
authors.affiliation: Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States.
authors.forename: C Travis
authors.initials: CT
authors.lastname: Powell
authors.forename: Keewook
authors.initials: K
authors.lastname: Paeng
authors.forename: Zhen
authors.initials: Z
authors.lastname: Chen
authors.forename: Ranko
authors.initials: R
authors.lastname: Richert
authors.forename: Lian
authors.initials: L
authors.lastname: Yu
authors.forename: M D
authors.initials: MD
authors.lastname: Ediger
mesh_terms: D003460:Crystallization; D005898:Glass; D015394:Molecular Structure; D009930:Organic Chemicals / Q000737:chemistry*; D013730:Terphenyl Compounds / Q000737:chemistry*
chemical_list: D009930:Organic Chemicals; D013730:Terphenyl Compounds