Temperature variation of effective geometry parameter, αg, refractive indices and the determination of orientational orders in three room temperature nematic liquid crystal mixtures

• Published in: Molecular crystals and liquid crystals (Philadelphia, Pa. : 2003) Pa. : 2003), 2016-01, Vol.625 (1), p.154-162
• Main Author: Pisipati, V. G. K. M.
• Format: Article
• Language: English
• Subjects: Effective geometry parameter; nematic room temperature LC mixtures; orientational order parameter; refractive indices
• ISSN: 1542-1406; 1563-5287
• DOI: 10.1080/15421406.2015.1081028

Orientational order parameter, S and effective geometry, α g are calculated from the refractive index in three nematic room temperature liquid crystal mixtures, blOO3, blOO6, and blO38. The method due to Kuczynski et al. used to determine S from birefringence. The effective geometry parameter is α g = n o /n e . (n o and n e are the ordinary and extraordinary refractive indices of the liquid crystal material.) The behavior of α g as a function of temperature and order parameter has also been reported. The S value calculated from α g is identically equal to the value obtained from Kuczynski et al method, i.e., from birefringence, δn. Finally, dn e /dT and dn o /dT are obtained and the crossover temperatures, T CO the characteristic temperature, which is in fact the temperature of minimum in the ordinary index of refraction in three mixtures for different wavelengths are calculated from dn o /dT.