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Hong F, Li H, Zhu D, Xia Z, Zhang H, Wang H, Zeng Z. Piperidine and 3,3,4,4,5,5-hexafluoropiperidine as terminal groups: Syntheses and properties as new liquid crystals. J Fluor Chem 2014. [DOI: 10.1016/j.jfluchem.2014.08.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Ilnytskyi JM, Trokhymchuk A, Schoen M. Topological defects around a spherical nanoparticle in nematic liquid crystal: Coarse-grained molecular dynamics simulations. J Chem Phys 2014; 141:114903. [DOI: 10.1063/1.4894438] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
- Jaroslav M. Ilnytskyi
- Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1, Svientsitskii Str., 79011 Lviv, Ukraine
| | - Andrij Trokhymchuk
- Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1, Svientsitskii Str., 79011 Lviv, Ukraine
| | - Martin Schoen
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Fakultät für Mathematik und Naturwissenschaften, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany and Department of Chemical and Biomolecular Engineering, Engineering Building I, Box 7905, North Carolina State University, 911 Partners Way, Raleigh, North Carolina 27695, USA
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Nagel G, Wölfel W, Noack F. Proton Spin Relaxation Dispersion for Some Nematic Homologues of the Liquid Crystal PAA. Isr J Chem 2013. [DOI: 10.1002/ijch.198300054] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Simeão DS, Simões M. Universality of the nematic mesophase. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:042701. [PMID: 23214632 DOI: 10.1103/physreve.86.042701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Indexed: 06/01/2023]
Abstract
This paper presents a detailed comparative study of published order-parameter experimental data of nematic liquid crystals. Throughout a simple linear transformation, it is shown that three distinct nematic mesophases exhibit the same and unique universal behavior for all temperatures below the nematic-isotropic phase transition. This paper generalizes a previous one [M. Simões, D. S. Simeão, S. M. Domiciano, and A. de Campos, Phys. Lett. A 372, 5346 (2008)], in which only the nematic mesophase delimited by the crystalline phase at low temperature was studied. Here we have assembled order-parameter experimental data of 61 different compounds, forming a set with data of 96 experiments, aiming to show that the nematic universal behavior is independent of what is the actual phase or mesophase bordering the nematic phase at low temperatures; our results show that all experimental data of all nematic mesophases coalesce along a common line that extends over the entire range of mesophases.
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Affiliation(s)
- D S Simeão
- Departamento de Física, Universidade Estadual de Londrina, Campus Universitário, 86051-990 Londrina, Paraná, Brazil
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Pisipati V, Madhavi Latha D, Datta Prasad P, Padmaja Rani G. Order parameter studies from effective order geometry in a number of liquid crystals of different homologous series. J Mol Liq 2012. [DOI: 10.1016/j.molliq.2012.07.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Roy PD, Das B, Das MK. Determination of the orientational order parameter of a binary mixture showing an induced smectic A(d) phase from magnetic susceptibility measurements. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:335108. [PMID: 21828602 DOI: 10.1088/0953-8984/21/33/335108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The diamagnetic susceptibility anisotropy (Δχ) measurement of a binary mixture comprising of a strongly polar mesogen (CPPCC) and a weakly polar mesogen (ME6O.5) showing an induced smectic A(d) phase is reported here. Assuming an axially symmetric molecule, the temperature dependence of the orientational order parameter ⟨P(2)⟩ has been investigated from the anisotropy of the susceptibility at different temperatures throughout the entire composition range. The results are compared with x-ray and optical birefringence measurements along with the mean-field theory of the smectic A phase. The maximum in the stability of the smectic A(d) phase (at x(CPPCC) = 0.33) corresponds to the minimum in the order parameter values. The order of the smectic to nematic phase transition has also been discussed.
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Affiliation(s)
- Prithwi Dev Roy
- Department of Physics, North Bengal University, Siliguri 734013, India
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Simões M, Simeão DS. Corresponding states of order parameter in nematic liquid crystals. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2006; 74:051701. [PMID: 17279920 DOI: 10.1103/physreve.74.051701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 09/15/2006] [Indexed: 05/13/2023]
Abstract
In this work, experimental data points from which the profile of the order parameter of nematic liquid crystals can be obtained, mainly magnetic susceptibility anisotropy and dielectric anisotropy, will be used to show that when rescaled they coalesce along a common line that extends from the nematic-isotropic phase transition region, until the nematic-crystalline phase transition region. A large set of experimental data of a diversity of nematic compounds that share the presence of a nematic-isotropic and a nematic-crystalline phase transition, without another phase within, has been collected from the liquid crystals literature. Taking for each of them the temperatures of these two phase transitions as fixed points, a common temperature scale has been constructed and, in this scale, the value of each physical quantity has been uniformly fixed at the nematic-crystalline phase transition temperature. This procedure has revealed the existence of a law of corresponding states that covers the entire nematic phase. As the values assumed by these physical quantities can be used to measure the macroscopic order parameter, the use of this temperature scale suggests that it presents a common behavior that covers the entire nematic phase.
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Affiliation(s)
- M Simões
- Departamento de Física, Universidade Estadual de Londrina, Campus Universitário, 86051-990 Londrina (PR), Brazil.
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8
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Singh S, Lahiri TK, Singh K. The Effect of Short-Range Orientational Order on the Nematic-Isotropic Phase Transition. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587259308036240] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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9
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Calucci L, Catalano D, Ghedini M, Jones NL, Pucci D, Veracini CA. 2H NMR Study of the Cyclopalladated 4,4′-Bis (Hexyloxy)-Azoxybenzene, a Complex Showing a Nematic Phase. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/10587259608031894] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Lucia Calucci
- a Dipartimento di Chimica e Chimica Industriale , Università degli Studi di Pisa , via Risorgimento 35, 56126 , Pisa , Italy
| | - Donata Catalano
- a Dipartimento di Chimica e Chimica Industriale , Università degli Studi di Pisa , via Risorgimento 35, 56126 , Pisa , Italy
| | - Mauro Ghedini
- b Dipartimento di Chimica , Università della Calabria , Arcavacata di Rende, 87030 , Cosenza , Italy
| | - Nicola L. Jones
- a Dipartimento di Chimica e Chimica Industriale , Università degli Studi di Pisa , via Risorgimento 35, 56126 , Pisa , Italy
| | - Daniela Pucci
- b Dipartimento di Chimica , Università della Calabria , Arcavacata di Rende, 87030 , Cosenza , Italy
| | - Carlo A. Veracini
- a Dipartimento di Chimica e Chimica Industriale , Università degli Studi di Pisa , via Risorgimento 35, 56126 , Pisa , Italy
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Jolley KW, Boden N, Parker D, Henderson JR. Nature of the liquid crystalline phase transitions in the cesium pentadecafluorooctanoate-water system: the nematic-to-smectic-A transition. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2002; 65:041713. [PMID: 12005852 DOI: 10.1103/physreve.65.041713] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2001] [Indexed: 05/23/2023]
Abstract
Measurements of the diamagnetic susceptibility chi(a), the rotational viscosity coefficient gamma(1), and the micellar orientational order parameter S have been made as a function of temperature across the entire nematic phases of cesium pentadecafluorooctanoate (CsPFO)-D2O samples over the concentration range weight fraction CsPFO w from 0.350 to 0.500. This has been chosen so as to embrace the pseudo-nematic phase-lamellar tricritical point that has been purported to occur at w=0.43 (volume fraction phi=0.26). The values of gamma(1) vary from about 0.1 kg m(-1) s(-1) to 1000 kg m(-1) s(-1) as the temperature decreases across the nematic phase, covering a much larger range than those reported for thermotropic liquid crystals. Measurements of gamma(1) have been made much closer to the critical temperature T(LN) than have previously been reported [(T-T(LN))/T(LN)=2 x 10(-5) for the w=0.350 sample]. The rotational viscosity critical exponents x calculated from the divergence of gamma(1) on approaching the nematic-phase-to-lamellar transition are found to be constant at 2/3 independent of the concentration. These values differ from those of 1/3 and 1/2, respectively, predicted by the He-like three-dimensional XY and mean-field models, in combination with mean-field dynamical relaxation. However, the former would be supported if complete Fisher renormalization (at alpha=1/2) was appropriate over an extended concentration range. Alternatively, this could be an indication of the importance of coupling between the micellar rotational dynamics and critical fluctuations since the latter are seen to be predominant across the entire temperature range of the nematic phase as revealed in the temperature dependence of gamma(1).
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Affiliation(s)
- K W Jolley
- Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
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11
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Ferrarini A, Moro GJ. Molecular order in nematic liquid crystals from shape-dependent repulsive and attractive interactions. J Chem Phys 2001. [DOI: 10.1063/1.1329136] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Marinelli M, Mercuri F. Effects of fluctuations in the orientational order parameter in the cyanobiphenyl (nCB) homologous series. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 2000; 61:1616-1621. [PMID: 11046444 DOI: 10.1103/physreve.61.1616] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/1999] [Revised: 09/07/1999] [Indexed: 05/23/2023]
Abstract
Photopyroelectric measurements of the anisotropy in the thermal conductivity Deltak vs temperature in the nCB (n=5,ellipsis,9) series are reported. The data have been used to deduce the behavior of the orientational order parameter Q close to the nematic-isotropic (N-I) and smectic A-nematic (A-N) phase transitions, respectively. It has been shown that near the N-I transition the data for 5CB and 6CB are consistent with the so-called "tricritical hypothesis," which predicts beta=0.25. This is not true for 7CB and 8CB in which the order parameter exhibits a behavior that could be caused by the presence of fluctuations that become increasingly important when the transition temperature is approached. A very simple model, which takes into account the contribution of fluctuations to the orientational order, has been developed close to the A-N transition and it has been shown that it is in good agreement with the experimental results. A semiquantitative explanation for the observed behavior in compounds with different nematic range has been also given.
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Affiliation(s)
- M Marinelli
- Dipartimento di Ingegneria Meccanica and Sezione, INFM Roma II, Universita di Roma "Tor Vergata," via di Tor Vergata 110, 00133 Rome, Italy
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Murthy YN, Murthy VR, Reddy RNVR. Polarizabilities and Related Properties of Azo Benzene Liquid Crystal Compounds. CRYSTAL RESEARCH AND TECHNOLOGY 1997. [DOI: 10.1002/crat.2170320211] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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14
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Anoardo E, Pusiol DJ. 14N nuclear quadrupole dips in the proton spin-lattice relaxation dispersion in the smectic-C phase of HpAB. PHYSICAL REVIEW LETTERS 1996; 76:3983-3986. [PMID: 10061162 DOI: 10.1103/physrevlett.76.3983] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Reddy RNVR, Murthy VR. Polarizabilities of Binary Mesophase Mixtures Containing 4,4′-Di-Ethoxy-Azoxybenzene. CRYSTAL RESEARCH AND TECHNOLOGY 1992. [DOI: 10.1002/crat.2170270724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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16
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Orientational-translational coupling for nematic-smectic-A tricritical point : A birefringence study. J Mol Liq 1991. [DOI: 10.1016/0167-7322(91)80029-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Palangana AJ. Measurements of the ratio between the bend elastic constant and the anisotropy of diamagnetic susceptibility of a lyotropic nematic liquid crystal as a function of the temperature. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1990; 41:7053-7055. [PMID: 9903125 DOI: 10.1103/physreva.41.7053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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18
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Venkatacharyulu P, Prasad KSR, Rao JV. Intermolecular free lengths and odd-even effect studies in certain alkoxy benzylidene butylanilines. CRYSTAL RESEARCH AND TECHNOLOGY 1989. [DOI: 10.1002/crat.2170240821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Kroin T, Palangana AJ. Determination of the bend elastic constant and the anisotropy of diamagnetic susceptibility of lyotropic nematic calamitic liquid crystals. PHYSICAL REVIEW. A, GENERAL PHYSICS 1989; 39:5373-5377. [PMID: 9901101 DOI: 10.1103/physreva.39.5373] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Limmer S. Physical Principles Underlying the Experimental Methods for Studying the Orientational Order of Liquid Crystals. ACTA ACUST UNITED AC 1989. [DOI: 10.1002/prop.2190371202] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Lampe MW, Collings PJ. High-pressure volumetric measurements near a smectic-nematic-isotropic triple point. PHYSICAL REVIEW. A, GENERAL PHYSICS 1986; 34:524-528. [PMID: 9897278 DOI: 10.1103/physreva.34.524] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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23
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van Dijk JW, Beens WW, de Jeu WH. Viscoelastic twist properties of some nematic liquid crystalline azoxybenzenes. J Chem Phys 1983. [DOI: 10.1063/1.446255] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Kneppe H, Reiffenrath V, Schneider F. Anisotropy of the magnetic susceptibility of some nematic liquid crystals. Chem Phys Lett 1982. [DOI: 10.1016/0009-2614(82)83554-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Limmer S, Findeisen M, Schmiedel H, Hillner B. Investigations on the ordering of five p, p'-di-n-alkyloxy-azoxybenzenes in their nematic phases by proton NMR. ACTA ACUST UNITED AC 1981. [DOI: 10.1051/jphys:0198100420120166500] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Influence of a Smectic Phase on Thermodynamical Behaviour of the Nematic to Isotropic Phase Transition. ACTA ACUST UNITED AC 1980. [DOI: 10.1007/978-3-642-67848-6_33] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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27
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Schad H, Baur G, Meier G. Investigation of the dielectric constants and the diamagnetic anisotropies of cyanobiphenyls (CB), cyanophenylcyclohexanes (PCH), and cyanocyclohexylcyclohexanes (CCH) in the nematic phase. J Chem Phys 1979. [DOI: 10.1063/1.438763] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Ibrahim I, Haase W. Molecular properties of some nematic liquids. II. Refractive index and order parameter. ACTA ACUST UNITED AC 1979. [DOI: 10.1051/jphys:01979004002019100] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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de Jeu WH, Bordewijk P. Physical studies of nematic azoxybenzenes. II. Refractive indices and the internal field. J Chem Phys 1978. [DOI: 10.1063/1.435499] [Citation(s) in RCA: 106] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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31
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Bordewijk P, de Jeu WH. Calculation of dipole correlation factors in liquid crystals with use of a semiempirical expression for the internal field. J Chem Phys 1978. [DOI: 10.1063/1.435500] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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