Title of article :
High-resolution FTIR study of the para-terphenyl phase transition at high pressure
Author/Authors :
Bohdan Schatschneider، نويسنده , , Eric L. Chronister، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2007
Pages :
7
From page :
34
To page :
40
Abstract :
High-resolution infrared (IR) spectroscopy has been used to investigate the pressure-induced (0–11 kbar) polymorphic phase transition of crystalline para-terphenyl at low temperature (25 K). A number of doublet bands observed in low-pressure triclinic p-terphenyl were observed to coalesce in the high-pressure monoclinic phase. The coalescing of doublet bands was attributed to changes in factor group (Davydov) splittings associated with the transition from a low-pressure triclinic phase to a high-pressure monoclinic phase. The bands that ‘disappear’ also do not correlate with frequency changes associated with changes in molecular symmetry. Molecular dynamics (MD) simulations at low temperature (20 K) yield a non-planar average molecular structure for the high-pressure monoclinic phase, in contrast to the high-temperature monoclinic phase. The MD simulations also reveal a broadening of the distribution of ring torsion angles near the triclinic–monoclinic phase transition pressure.
Keywords :
high-pressure , Molecular crystal , Low-temperature , p-Terphenyl , high-resolution , Infrared
Journal title :
Journal of Luminescence
Serial Year :
2007
Journal title :
Journal of Luminescence
Record number :
1263066
Link To Document :
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