Bend and splay elastic constants of diheptylazoxybenzene

Shila Garg; Karl A. Crandall; Asad A. Khan

doi:10.1103/PhysRevE.48.1123

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Bend and splay elastic constants of diheptylazoxybenzene

Shila Garg, Karl A. Crandall, and Asad A. Khan

Physics Department, College of Wooster, Wooster, Ohio 44691

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Phys. Rev. E 48, 1123 – Published 1 August, 1993

DOI: https://doi.org/10.1103/PhysRevE.48.1123

Abstract

In this study we report the values of the bend ( $K_{3}$ ) and splay ( $K_{1}$ ) elastic constants of the nematic liquid crystal diheptylazoxybenzene, using a Fréedericksz-transition technique. Both the bend and the splay constants were measured over a range of temperatures approaching the nematic–smectic-A (NA) transition. The ratios of $K_{3}$ / $K_{1}$ follow the trend of increasing towards the NA transition, which makes the conditions favorable, in the homeotropic geometry, for striped instabilities to set in. The value of $K_{3}$ / $K_{1}$ for our material is fairly small at higher temperatures when compared to similar materials, which is consistent with the decreasing of $K_{3}$ / $K_{1}$ with an increasing alkyl-chain length. The bend critical exponent $ρ_{3}$ was determined to be 0.68±0.04, which is in close agreement with a prediction of de Gennes [Solid State Commun. 10, 753 (1972)]. The effect of the nematic range on this critical exponent is examined in terms of a critical-multicritical crossover.

References (43)

T. C. Lubensky, J. Phys. (Paris) 80, 31 (1983).
P. G. de Gennes, Solid State Commun. 10, 753 (1972); Mol. Cryst. Liq. Cryst. 21, 149 (1973) also see, for example, Shang-Ke Ma, Modern Theory of Critical Phenomena (Benjamin, New York, 1976).
C. Dasgupta and B. I. Halperin, Phys. Rev. Lett. 47, 1556 (1981).
W. Helfrich, J. Phys. (Paris) 39, 1199 (1978).
W. L. McMillan, Phys. Rev. A 4, 1238 (1971).
K. K. Kobayashi, Phys. Lett. 31A, 125 (1970).
J. Thoen, H. Marynissen and W. Van Dael, Phys. Rev. Lett. 52, 204 (1984).
D. Brisbin, R. deHoff, T. Lockhart and D. L. Johnson, Phys. Rev. Lett. 43, 1171 (1979).
B. M. Ocko, R. J. Birgeneau, J. D. Litster and M. E. Neubert, Phys. Rev. Lett. 52, 208 (1984).
G. Vertogen and W. H. de Jeu, Thermotropic Liquid Crystals, Fundamentals (Springer-Verlag, New York, 1988).
D. L. Johnson, C. Maze, E. Oppenheim and R. Reynolds, Phys. Rev. Lett. 34, 1143 (1975).
H. K. M. Vithana, V. Surendranath, M. Lewis, A. Baldwin, K. Eidner, R. Mahmood and D. L. Johnson, Phys. Rev. A 41, 2031 (1990).
D. L. Johnson, J. Phys. (Paris) 80, 45 (1983).
W. H. de Jeu and W. A. P. Claassen, J. Chem. Phys. 67, 3705 (1977).
W. H. de Jeu and P. Bordewijk, J. Chem. Phys. 109, 68 (1978).
W. H. de Jeu and W. A. P. Claassen, J. Chem. Phys. 102, 68 (1978).
W. H. de Jeu, W. J. A. Goossens and P. Bordewijk, J. Chem. Phys. 61, 1985 (1974).
Hemasiri Vithana, Ph.D. thesis, Kent State University, 1990 (unpublished); H. K. M. Vithana, G. Xu and D. L. Johnson, Phys. Rev. E 47, 3441 (1993).
V. Fréederickz and V. Zolina, Trans. Faraday Soc. 29, 919 (1933).
P. G. de Gennes, The Physics of Liquid Crystals (Clarendon, Oxford, 1974).
F. Jahnig and F. Brochard, J. Phys. (Paris) 35, 301 (1974).
Frederic J. Kahn, J. Appl. Phys. Lett. 22, 386 (1973).
Peter J. Collings and J. Patel (private communication).
C. Gooden, R. Mahmood, D. Brisbin, A. Baldwin, D. L. Johnson and M. E. Neubert, Phys. Rev. Lett. 54, 1035 (1985), and references contained therein.
D. L. Johnson (private communication).
Li Chen, Liquid Crystal Institute, Kent, OH, measurement of $q_{0}$ for $C_{7}$ (private communication).
Lawrence Chueng, Robert B. Meyer and Hans Gruler, Phys. Rev. Lett. 31, 349 (1973).
D. W. Allender, R. M. Hornreich and D. L. Johnson, Phys. Rev. Lett. 59, 2654 (1987).
U. D. Kini, Liq. Cryst. 7, 185 (1990).
P. Cladis and S. Torza, J. Appl. Phys. 46, 584 (1975).
Ivan Haller, J. Chem. Phys. 57, 1400 (1972).
W. H. de Jeu, Physical Properties of Liquid Crystalline Materials (Gordon and Breach, New York, 1980), and references contained therein.
M. J. Bradshaw, E. P. Raynes, J. D. Bunning and T. E. Faber, J. Phys. (Paris) 46, 1513 (1985).
M. Achard, F. Hardouin, G. Sigaud and H. Gasparoux, J. Chem. Phys. 65, 1387 (1976).
J. W. Doane, R. S. Parker, B. Cvikl, D. L. Johnson and D. L. Fishel, Phys. Rev. Lett. 28, 1694 (1975).
Bruce R. Patton and Barbara Andereck, Phys. Rev. Lett. 69, 1556 (1992).
Stephen Morris, P. Palffy-Muhoray and D. A. Balzarini, Mol. Cryst. Liq. Cryst. 139, 263 (1986).
D. Davidov, C. R. Safinya, M. Kaplan, S. S. Dana, R. Schaetzing, R. J. Birgeneau and J. D. Litster, Phys. Rev. B 19, 1657 (1979).
S. Sprunt, L. Solomon and J. D. Litster, Phys. Rev. Lett. 53, 1923 (1984).
M. Delaye, R. Ribotta and G. Durand, Phys. Rev. Lett. 31, 443 (1973).
Als-Nielsen, R. J. Birgeneau, M. Kaplan, J. D. Litster and C. R. Safinya, Phys. Rev. Lett. 39, 352 (1977).
C. W. Garland, M. Meichle, B. M. Ocko, A. R. Kortan, C. R. Safinya, L. J. Yu, J. D. Litster and R. J. Birgeneau, Phys. Rev. A 27, 3234 (1983).
Li Chen, J. D. Brock, J. Huang and Satyendra Kumar, Phys. Rev. Lett. 67, 2037 (1991).

[c1] T. C. Lubensky, J. Phys. (Paris) 80, 31 (1983).

[c2] P. G. de Gennes, Solid State Commun. 10, 753 (1972); Mol. Cryst. Liq. Cryst. 21, 149 (1973) also see, for example, Shang-Ke Ma, Modern Theory of Critical Phenomena (Benjamin, New York, 1976).

[c3] C. Dasgupta and B. I. Halperin, Phys. Rev. Lett. 47, 1556 (1981).

[c4] W. Helfrich, J. Phys. (Paris) 39, 1199 (1978).

[c5] W. L. McMillan, Phys. Rev. A 4, 1238 (1971).

[c6] K. K. Kobayashi, Phys. Lett. 31A, 125 (1970).

[c7] J. Thoen, H. Marynissen and W. Van Dael, Phys. Rev. Lett. 52, 204 (1984).

[c8] D. Brisbin, R. deHoff, T. Lockhart and D. L. Johnson, Phys. Rev. Lett. 43, 1171 (1979).

[c9] B. M. Ocko, R. J. Birgeneau, J. D. Litster and M. E. Neubert, Phys. Rev. Lett. 52, 208 (1984).

[c10] G. Vertogen and W. H. de Jeu, Thermotropic Liquid Crystals, Fundamentals (Springer-Verlag, New York, 1988).

[c11] D. L. Johnson, C. Maze, E. Oppenheim and R. Reynolds, Phys. Rev. Lett. 34, 1143 (1975).

[c12] H. K. M. Vithana, V. Surendranath, M. Lewis, A. Baldwin, K. Eidner, R. Mahmood and D. L. Johnson, Phys. Rev. A 41, 2031 (1990).

[c13] D. L. Johnson, J. Phys. (Paris) 80, 45 (1983).

[c14] W. H. de Jeu and W. A. P. Claassen, J. Chem. Phys. 67, 3705 (1977).

[c15] W. H. de Jeu and P. Bordewijk, J. Chem. Phys. 109, 68 (1978).

[c16] W. H. de Jeu and W. A. P. Claassen, J. Chem. Phys. 102, 68 (1978).

[c17] W. H. de Jeu, W. J. A. Goossens and P. Bordewijk, J. Chem. Phys. 61, 1985 (1974).

[c18] Hemasiri Vithana, Ph.D. thesis, Kent State University, 1990 (unpublished); H. K. M. Vithana, G. Xu and D. L. Johnson, Phys. Rev. E 47, 3441 (1993).

[c19] V. Fréederickz and V. Zolina, Trans. Faraday Soc. 29, 919 (1933).

[c20] P. G. de Gennes, The Physics of Liquid Crystals (Clarendon, Oxford, 1974).

[c21] F. Jahnig and F. Brochard, J. Phys. (Paris) 35, 301 (1974).

[c22] Frederic J. Kahn, J. Appl. Phys. Lett. 22, 386 (1973).

[c23] Peter J. Collings and J. Patel (private communication).

[c24] C. Gooden, R. Mahmood, D. Brisbin, A. Baldwin, D. L. Johnson and M. E. Neubert, Phys. Rev. Lett. 54, 1035 (1985), and references contained therein.

[c25] D. L. Johnson (private communication).

[c26] Li Chen, Liquid Crystal Institute, Kent, OH, measurement of $q_{0}$ for $C_{7}$ (private communication).

[c27] Lawrence Chueng, Robert B. Meyer and Hans Gruler, Phys. Rev. Lett. 31, 349 (1973).

[c28] D. W. Allender, R. M. Hornreich and D. L. Johnson, Phys. Rev. Lett. 59, 2654 (1987).

[c29] U. D. Kini, Liq. Cryst. 7, 185 (1990).

[c30] P. Cladis and S. Torza, J. Appl. Phys. 46, 584 (1975).

[c31] Ivan Haller, J. Chem. Phys. 57, 1400 (1972).

[c32] W. H. de Jeu, Physical Properties of Liquid Crystalline Materials (Gordon and Breach, New York, 1980), and references contained therein.

[c33] M. J. Bradshaw, E. P. Raynes, J. D. Bunning and T. E. Faber, J. Phys. (Paris) 46, 1513 (1985).

[c34] M. Achard, F. Hardouin, G. Sigaud and H. Gasparoux, J. Chem. Phys. 65, 1387 (1976).

[c35] J. W. Doane, R. S. Parker, B. Cvikl, D. L. Johnson and D. L. Fishel, Phys. Rev. Lett. 28, 1694 (1975).

[c36] Bruce R. Patton and Barbara Andereck, Phys. Rev. Lett. 69, 1556 (1992).

[c37] Stephen Morris, P. Palffy-Muhoray and D. A. Balzarini, Mol. Cryst. Liq. Cryst. 139, 263 (1986).

[c38] D. Davidov, C. R. Safinya, M. Kaplan, S. S. Dana, R. Schaetzing, R. J. Birgeneau and J. D. Litster, Phys. Rev. B 19, 1657 (1979).

[c39] S. Sprunt, L. Solomon and J. D. Litster, Phys. Rev. Lett. 53, 1923 (1984).

[c40] M. Delaye, R. Ribotta and G. Durand, Phys. Rev. Lett. 31, 443 (1973).

[c41] Als-Nielsen, R. J. Birgeneau, M. Kaplan, J. D. Litster and C. R. Safinya, Phys. Rev. Lett. 39, 352 (1977).

[c42] C. W. Garland, M. Meichle, B. M. Ocko, A. R. Kortan, C. R. Safinya, L. J. Yu, J. D. Litster and R. J. Birgeneau, Phys. Rev. A 27, 3234 (1983).

[c43] Li Chen, J. D. Brock, J. Huang and Satyendra Kumar, Phys. Rev. Lett. 67, 2037 (1991).

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Bend and splay elastic constants of diheptylazoxybenzene

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