Theoretical Study of the Effect of Light on Nematic to Isotropic Phase Transition

• Authors: B. Suresha , M. Radhakrishna , A. Govind
• Languages of publication: EN

Abstracts

EN

Optical response of liquid crystals is very important from the point of view of applications of liquid crystals in display and data storage devices. Experiments have shown that UV rays incident on nematic liquid crystals doped with photoactive azo compounds lower the nematic isotropic transition temperature (T_{NI}). This is attributed to the transformation of photoactive trans isomer to cis isomer due to UV rays. We have earlier developed a mean field model involving molecular explanation for two lengths in which the mutual orientation of near neighbor molecules changes from an antiparallel to a parallel configuration as the temperature lowered. In this paper, this model is extended to include the length change from trans to cis isomer. The calculated values of change in T_{NI} qualitatively agree with experimental trends.

Keywords

EN

61.30.-v; 64.70.M-

Discipline

• 61.30.-v: Liquid crystals(for phase transitions in liquid crystals, see 64.70.M-; for liquid crystals as dielectric materials, see 77.84.Nh; for liquid crystals as optical materials, see 42.70.Df; for liquid crystal devices, see 42.79.Kr)
• 64.70.M-: Transitions in liquid crystals

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2011
• Volume: 120
• Issue: 3
• Pages: 462-467

Dates

published

2011-09

received

2010-08-18

(unknown)

2011-04-20

Contributors

author

B. Suresha

• Dept. of Physics, Bangalore University, Bangalore, 560 056, India

author

M. Radhakrishna

• Dept. of Physics, Bangalore University, Bangalore, 560 056, India

author

A. Govind

• Dept. of Physics, Vijaya Degree College, Bangalore, 560 004, India

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Identifiers

DOI

10.12693/APhysPolA.120.462