Raman depolarization ratios and order parameters of a nematic liquid crystal

Journal Article · Fri Dec 01 04:00:00 EST 1978 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.436508· OSTI ID:6627348

Miyano, K

The depolarization ratios of the Raman vibrational bands from the terminal CequivalentN and the central C--C biphenyl link of an oriented nematic liquid crystal (p-n-pentyl-p'-cyanobiphenyl (5CB)) have been measured. The orientational order parameters

and

were calculated. The parameter

remained far less than the mean-field theory prediction although a systematic discrepancy between the order parameters obtained from the two bands was noted. The Raman tensor of CequivalentN band was found not to be uniaxial, contrary to the previous assumption, and a strong association of molecules is suggested. Problems associated with this technique are discussed.

• Research Organization: Argonne National Laboratory, Argonne, Illinois 60439
• OSTI ID: 6627348
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 69:11; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640300* -- Atomic
Molecular & Chemical Physics
74 ATOMIC AND MOLECULAR PHYSICS
CRYSTALS
DEPOLARIZATION
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
FLUIDS
LIQUID CRYSTALS
LIQUIDS
ORDER PARAMETERS
RAMAN EFFECT
SPECTRA
VIBRATIONAL STATES