TY - JOUR
T1 - Fast crystal growth from organic glasses
T2 - Comparison of o-terphenyl with its structural analogs
AU - Powell, C. Travis
AU - Paeng, Keewook
AU - Chen, Zhen
AU - Richert, Ranko
AU - Yu, Lian
AU - Ediger, M. D.
PY - 2014/7/17
Y1 - 2014/7/17
N2 - 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, u kin ∝ 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.
AB - 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, u kin ∝ 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.
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U2 - 10.1021/jp501301y
DO - 10.1021/jp501301y
M3 - Article
C2 - 24654628
AN - SCOPUS:84900998204
SN - 1520-6106
VL - 118
SP - 8203
EP - 8209
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 28
ER -