, Volume 6, Issue 5, pp 278–283 | Cite as

Dielectric properties of 4′-n-alkyl-4-cyanobiphenyls in their nematic phases

  • B R Ratna
  • R Shashidhar


The principal dielectric constants of the pentyl to octyl derivatives of 4′-n-alkyl-4-cyanobiphenyl have been measured as functions of temperature in their nematic and isotropic phases. All the compounds exhibit a strong positive dielectric anisotropy due to the presence of a large dipole moment along the major molecular axis. The principal dielectric constantsε andε as well as the anisotropy Δε decrease with increasing alkyl chain length. The experimental value of\(\bar \in = \frac{1}{3}\)+2ε) decreases with decreasing temperature, and is throughout less than the extrapolated isotropic value, in conformity with the model of antiferroelectric short range order proposed by Madhusudana and Chandrasekhar.


Nematic liquid crystals dielectric anisotropy cyanobiphenyl 


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Copyright information

© Indian Academy of Sciences 1976

Authors and Affiliations

  • B R Ratna
    • 1
  • R Shashidhar
    • 1
  1. 1.Raman Research InstituteBangalore

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