[PDF]    http://dx.doi.org/10.3952/physics.v55i1.3055

Open access article / Atviros prieigos straipsnis

Lith. J. Phys. 55, 2434 (2015)

Arif Nesrullajev
Department of Physics, Faculty of Science, Mugla Sitki Koçman University, 48000 Kötekli Muğla, Turkey
E-mail: arifnesr@mu.edu.tr

Received 1 October 2014; revised 25 November 2014; accepted 10 December 2014

Investigations of temperature behaviour of the mean refractive index n, ordinary no and extraordinary ne refractive indices, and birefringence Δn have been carried out for three homologues of 4-n-alkyl-4'-cyanobiphenyls (n = 8, 10, 12). The principal polarizabilities α0 and αe, effective geometry parameter αeg and average polarizability αave have been calculated using the isotropic internal field model (Vuks approach). Temperature behaviour of the order parameter in regions of the smectic A–nematic, nematic–isotropic liquid and smectic A–isotropic liquid is discussed. All of the optical and orientational parameters, which have been obtained in this work, are in good agreement with the theoretical approach.
Keywords: liquid crystals, refractive properties, optical birefringence, phase transitions
PACS: 42.25.Lc; 42.70.Df; 64.70.M


Arif Nesrullajev
Mugla Sitki Koçman universiteto Mokslo fakulteto Fizikos katedra, Kötekli Muğla, Turkija

References / Nuorodos

[1] L.M. Blinov and V.G. Chigrinov, Electrooptic Effects in Liquid Crystal Materials (Springer Verlag, New York, 1993),
[2] M.A. Anisimov, Critical Phenomena in Liquids and Liquid Crystals (Gordon and Breach Science Publishers, New York–London, 1991),
[3] P. Yeh and C. Gu, Optics of Liquid Crystal Displays (Wiley Publishing, London–New York, 2009)
[4] I.C. Khoo, Liquid Crystals (Wiley Publishing, London–New York, 2007),
[5] H.S. Subramhanyam, C.S. Prabha, and D. Krishnamurti, Optical anisotropy of nematic compounds, Mol. Cryst. Liq. Cryst. 28, 201–215 (1974),
[6] A. Nesrullajev, A.S. Sonın, and A.Z. Rabinovich, Study of the character of smectic A–nematic phase transitions in cyanobiphenyl mixtures, Crystallography 25, 435–439 (1980) [in Russian]
[7] M. Mitra, S. Gupta, R. Paul, and S. Paul, Determination of orientational order parameter from optical studies for a homologous series of mesomorphic compounds, Mol. Cryst. Liq. Cryst. 199, 257–266 (1991),
[8] M.S. Zakerhamidi, Z. Ebrahimi, H. Tajalli, A. Ghanadzadeh, M. Modhadam, and A. Ranjkesh, Refractive indices and order parameters of some tolane-based nematic liquid crystals, J. Mol. Liq. 157, 119–124 (2010),
[9] K. Bhowmick, A. Mukhopadhyay, and C.D. Mukherjee, Texture and optical studies of the mesophases of cyanocyclohexyl cyclohexanes, Phase Transit. 76, 671–682 (2003),
[10] M.F. Vuks, Determination of optical anisotropy of aromatic molecules from double refraction in crystals, Opt. Spectrosc. 20, 361–368 (1966) [in Russian]
[11] M.F. Vuks, Electrical and Optical Properties of Molecules and Condensed Matter (Leningrad University Publishing House, Leningrad, 1984) [in Russian]
[12] H.E.J. Neugebauer, Clausius–Mossotti equation for certain types of anisotropic crystals, Can. J. Phys. 32, 1–8 (1954),
[13] H.S. Subramhanyam and D. Krishnamurti, Polarization field and molecular order in nematic liquid crystals, Mol. Cryst. Liq. Cryst. 22, 239–248 (1973),
[14] D. Bhuyan, P. Pardhasarathi, K.N. Singh, D. Mathavi Latha, P.V. Datta Prasad, P.R. Alapati, and V.G.K.M. Pisipati, Study of molecular polarizabilities and orientational order parameter in the nematic phase of 6.0120.6 and 7.0120.7, World J. Condens. Matter. Phys. 1, 167–174 (2011),
[15] S.S. Sastry, T.V. Kumari, K. Mallika, B.G. Sankara Rao, S.-T. Ha, and S. Lakshminarayana, Order parameter studies on EPAP alcanoate mesogens, Liq. Cryst. 39, 295–301 (2012),
[16] I. Haller, Thermodynamic and static properties of liquid crystals, Progr. Solid State Chem. 10, 103–118 (1975),
[17] I. Haller, H.A. Huggins, H.R. Lilienthal, and T.R. McGuire, Order-related properties of some nematic liquids, J. Phys. Chem. 77, 950–954 (1973),
[18] I. Haller, H.A. Huggins, and M.H. Freiser, On the measurement of indices of refraction of nematic liquid crystals, Mol. Cryst. Liq. Cryst. 16, 53–59 (1972),
[19] M. Sharma, C. Kaur, J. Kumar, K.C. Singh, and P.C. Jain, Phase transformations in some homologues of 4-n-alkyl-4'-cyanobiphenyls investigated by positron annihilation spectroscopy, J. Phys. Condens. Matter. 13, 7249–7258 (2001),
[20] I. Chirtoc, M. Chirtoc, C. Glorieux, and J. Thoen, Determination of the order parameter and its critical exponent for nCB (n = 5–8) liquid crystals from refractive index data, Liq. Cryst. 31, 229–240 (2004),
[21] R.-P. Pan, T.-R. Tsai, C.-Y. Chen, C.-H. Wang, and C.-L. Pan, The refractive indices of nematic liquid crystal 4'-n-pentyl-4-cyanobiphenyl in the THz frequency range, Mol. Cryst. Liq. Cryst. 409, 137–144 (2004),
[22] G. Chahine, A.N. Kityk, N. Demarest, F. Jean, K. Knorr, P. Huber, R. Lefort, J.-M. Zanotti, and D. Morineau, Collective molecular reorientation of a calamitic liquid crystal (12CB) confined in alumina nanochannels, Phys. Rev. E 82, 011706 (2010),
[23] T. Nose, S. Sato, K. Mizuno, J. Bae, and T. Nozukido, Refractive index of nematic liquid crystals in the submillimeter wave region, Appl. Opt. 36, 6383–6387 (1997),
[24] S.K. Sarkar, P.C. Barman, and M.K. Das, Determination of optical birefringent and orientational order parameter of four members of alkyl cyanobiphenyls using high resolution temperature scanning technique, Int. J. Res. Appl. Nat. Soc. Sci. 1(4), 1–8 (2013)
[25] S. Chandrasekhar and N.V. Madhusudana, Orientational order in p-azoxyanisole, p-azoxyphenetole and their mixtures in nematic phase, J. Phys. Colloques 30, C4–24 (1969),
[26] N.V. Madhusudana and R. Pratibha, Elasticity and orientational order in some cyanobiphenyls: Part IV. Reanalysis of the data, Mol. Cryst. Liq. Cryst. 89, 249–257 (1982),
[27] T.N. Soorya, S. Gupta, A. Kumar, S. Jain, V.P. Arora, and B. Bahadur, Temperature dependent optical property studies of nematic mixtures, Indian J. Pure Appl. Phys. 44, 524–531 (2006),
[28] A. Kumar, Determination of orientational order and effective geometry parameter from refractive indices of some nematics, Liq. Cryst. 40, 503–510 (2013),
[29] P.V. Adomenas, A.N. Nesrullajev, B.I. Ostrovski, A.Z. Rabinovich, and A.S. Sonin, The change of the character of smectic A–nematic phase transition in binary mixtures of liquid crystals, Phys. Solid State 21, 2492–2496 (1979) [in Russian]
[30] A.S. Sonin, Introduction to the Physics of Liquid Crystals (Science Publishing House, Moscow, 1983) [in Russian]
[31] J.C. Tolédano and P. Tolédano, The Landau Theory of Phase Transitions (World Scientific, Singapore, 1987),
[32] M.A. Anisimov, Critical phenomena in liquid crystals, Mol. Cryst. Liq. Cryst. 162(1), 1–96 (1988),
[33] R. Manohar and J.P. Shukla, Refractive indices, order parameter and principal polarizability of cholesteric liquid crystals and their homogeneous mixtures, J. Phys. Chem. Solids 65, 1643–1650 (2004),
[34] W.H. de Jeu, Physical Properties of Liquid Crystalline Materials (Gordon and Breach, New York–London–Paris, 1980),
[35] A. Prasad and M.K. Das, Optical birefringence studies of a binary mixture with the nematic–smectic Ad–re-entrant nematic phase sequence, J. Phys. Condens. Matter. 22, 1–7 (2010),
[36] M. Ramakrishna, N. Rao, P.V. Datta Prasad, and V.G.K.M. Prisipati, Orientational order parameter in alkoxy benzoic acids – Optical studies, Mol. Cryst. Liq. Cryst. 528, 49–63 (2010),
[37] J.L. Kumari, P.V.D. Prasad, D.M. Latha, and V.G.K.M. Pisipati, Orientational order parameter estimated from molecular polarizabilities – an optical study, Phase Trans. 85, 52–64 (2012),
[38] P.V. Datta Prasad and V.G.K.M. Pisipati, Simple, accurate and low cost optical techniques for the measurement of 1. Birefringence in liquid crystal and 2. Variation of the angle of the small angled prism with temperature, Mol. Cryst. Liq. Cryst. 511, 102–111 (2009),
[39] W. Kuczynski, B.J. Zywicki, and J. Malecki, Determination of orientational order parameter in various liquid crystalline phases, Mol. Cryst. Liq. Cryst. 381, 1–19 (2002),
[40] A.K. Srivastava, R. Manohar, and J.P. Shukla, Refractive indices, order parameter and principal polarizability of cholesteric liquid crystals and their mixtures, Mol. Cryst. Liq. Cryst. 454, 225–234 (2006),
[41] S.S. Sastry, T.V. Kumari, S.S. Begum, and V.V. Rao, Investigations into effective order geometry in a series of liquid crystals, Liq. Cryst. 38, 277–285 (2011),
[42] M.D. Gupta, A. Mukhopadhyay, and K. Czuprynski, Optical properties of two liquid crystal compounds: a comparative study, Phase Trans. 83, 284–292 (2010),
[43] C. Satiro and F. Moraes, On the deflection of light by topological defects in nematics liquid crystals, Eur. Phys. J. 25, 425–429 (2008),
[44] C. Satiro and F. Moraes, Lensing effects in a nematic liquid crystal with topological defects, Eur. Phys. J. E 20, 173–178 (2006),
[45] M.M.M. Abdoh, S.N.C. Shivaprakash, and J.S. Prasad, Orientational order in the nematogenic homologous series trans-4-alkyl (4-cyanobiphenyl)-cyclohexane, J. Chem. Phys. 77, 2570–2576 (1982),
[46] A. Kumar, Determination of orientational order and effective geometry parameter from refractive indices of some nematics, Liq. Cryst. 40, 503–510 (2013),
[47] W.H. de Jeu and P. Bordewijk, Physical studies of nematic azoxybenzenes. II. Refractive indices and the internal field, J. Chem. Phys. 68, 109–115 (1978),
[48] W.L. McMillan, Simple molecular model for the smectic A phase of liquid crystals, Phys. Rev. A 4, 1238–1246 (1971),
[49] P.G. de Gennes and J. Prost, The Physics of Liquid Crystals (Oxford Science Publications, Oxford–London, 2003),
[50] P.G. de Gennes, The Physics of Liquid Crystals (Clarendon Press, Oxford–London, 1973)
[51] G. Chahine, A.N. Kityk, K. Knorr, R. Lefort, M. Guendouz, D. Morineau, and P. Huber, Criticality of an isotropic-to-smectic transition induced by anisotropic quenched disorder, Phys. Rev. E 81, 031703 (2010),
[52] B.M. Ocko, A. Braslau, P.S. Pershan, J. Als-Nielsen, and M. Deursch, Quantized layer growth at liquid-crystal surfaces, Phys. Rev. Lett. 57, 94–97 (1986),
[53] A. Nesrullajev and Ş. Oktik, Induced changes of smectic A–isotropic liquid phase transition peculiarities: Effect of surfaces, Mod. Phys. Lett. B 14, 821–833 (2006),
[54] N. Yilmaz-Canli, A. Nesrullajev, and B. Bilgin Eran, Synthesis, mesomorphic and physical properties of two new analogs of Schiff's base with an alkenic terminal chains, J. Mol. Str. 990, 79–85 (2011),
[55] A. Drozd-Rzoska, Influence of measurement frequency on the pretransitional behaviour of the nolinear dielectric effect in the isotropic phase of liquid crystalline materials, Liq. Cryst. 24, 835–840 (1998),
[56] A. Drozd-Rzoska, S.J. Rzoska, and J. Ziolo, Quasicritical behaviour of dielectric permittivity in the isotropic phase of smectogenic n-cyanobiphenyls, Phys. Rev. E 61, 5349–5344 (2000),
[57] S.G. Polushin, V.B. Rogozhin, E.I. Ryumtsev, and A.L. Lezov, The kerr effect in the vicinity of the transition from the isotropic to smectic A phase, Russ. J. Phys. Chem. 80, 1016–1020 (2006),
[58] S.J. Rzoska, P.K. Mukherjee, and M. Rutkowska, Does the characteristic value of the discontinuity of the isotropic–mesophase transition in n-cyanobiphenyls exist? J. Phys. Condens. Matter. 24, 375101 (2012),
[59] K.P. Sidgel and G.S. Innachione, Study of the isotropic to smectic-A phase transition in liquid crystal and acetone binary mixtures, J. Chem. Phys. 133, 174501 (2010),
[60] M. Olbrich, H.R. Brand, H. Finkelmann, and K. Kavasaki, Fluctuations above the smectic-A–isotropic transition in liquid crystalline elastomers under external stress, Europhys. Lett. 31, 281–286 (1995),
[61] G. Gordoyiannis, L.F.V. Pinto, M.H. Godinho, C. Glorieux, and J. Thoen, High-resolution calorimetric study of the phase transitions of tridecylcyanobiphenyl and terradecylcyanobiphenyl liquid crystals, Phase Trans. 82, 280–289 (2009),
[62] H. Pleiner, P.K. Mukherjee, and H.R. Brand, Direct transitions from isotropic to smectic phases, in: Proceedings of the 29th Freiburger Arbeitstagung Flüssigkristalle (2000) pp. 59–62
[63] H.R. Brand, P.K. Mukherjee, and H. Pleiner, Macroscopic dynamics near the isotropic–smectic-A phase transition, Phys. Rev. E 63, 061708–1 (2001),
[64] P.K. Mukherjee, H. Pleiner, and H.R. Brand, Simple Landau model of the smectic-A–isotropic phase transition, Eur. Phys. J. 4, 293–297 (2001),
[65] P.K. Mukherjee and S.J. Rzoska, Pressure effect on the smectic-A–isotropic phase transition, Phys. Rev. E 65, 051705 (2002),
[66] P.K. Mukherjee, Isotropic to smectic-A phase transition: A review, J. Mol. Liq., 190, 99–111 (2014),