Abstract
The high-resolution adiabatic scanning calorimetric technique has been used to investigate the nematic-smectic A transition (N-SmA in binary mixtures of the non-smectogenic liquid crystal heptyloxycyanobiphenyl (7OCB) and heptane, exhibiting a so-called injected smectic A phase. With the exception of a mixture with the lowest heptane mole fraction for which only an upper limit of 0.2 ± 0.2 J kg−1 for a possible latent heat could be obtained, for all other mixtures finite latent heats were obtained. The mole fraction dependence of the latent heat could be well fitted with a crossover function consistent with a mean-field free energy expression with a non-zero cubic term arising from the Halperin-Lubensky-Ma (HLM) coupling between the SmA order parameter and the orientational director fluctuations. The mole fraction dependence of the heat capacity effective critical exponents is similar to that observed in mixtures of the two liquid crystals octyloxycyanobiphenyl (8OCB) and nonylcyanobiphenyl (9OCB). The thermal behavior observed along the N-SmA phase transition line yields further strong evidence for the HLM coupling effect.
Similar content being viewed by others
References
P.G. de Gennes, J. Prost, The Physics of Liquid Crystals (Clarendon, Oxford, 1993).
G.B. Kasting, K.J. Lushington, C.W. Garland, Phys. Rev. B 22, 321 (1980).
J. Thoen, H. Marynissen, W. Van Dael, Phys. Rev. A 26, 2886 (1982).
J. Thoen, H. Marynissen, W. Van Dael, Phys. Rev. Lett. 52, 204 (1984).
C.W. Garland, G. Nounesis, Phys. Rev. E 49, 2964 (1994).
J. Thoen, G. Cordoyiannis, C. Glorieux, Liq. Cryst. 36, 669 (2009).
K. Kobayashi, Phys. Lett. A 31, 125 (1970).
W.L. MacMillan, Phys. Rev. A 4, 1238 (1971).
P.G. de Gennes, Mol. Cryst. Liq. Cryst. 21, 49 (1973).
B.I. Halperin, T.C. Lubensky, S.K. Ma, Phys. Rev. Lett. 32, 292 (1974).
H. Marynissen, J. Thoen, W. Van Dael, Mol. Cryst. Liq. Cryst. 124, 195 (1985).
M.A. Anisimov, V.P. Voronov, A.O. Kulkov, V.N. Petukhov, F. Kholmurodov, Mol. Cryst. Liq. Cryst. 150b, 399 (1987).
M.A. Anisimov, V.P. Voronov, E.E. Gorodetskii, V.E. Podneks, F. Kholmodurov, JETP Lett. 45, 425 (1987).
M.A. Anisimov, P. Cladis, E. Gorodetskii, D. Huse, V. Podneks, V. Taratuta, W. van Saarloos, V. Voronov, Phys. Rev. A 41, 6749 (1990).
G. Cordoyiannis, C.S.P. Tripathi, C. Glorieux, J. Thoen, Phys. Rev. E. 82, 031707 (2010).
J. Thoen, Int. J. Mod. Phys. B 9, 2157 (1995).
J. Caerels, C. Glorieux, J. Thoen, Phys. Rev. E 65, 031704 (2002).
K. Denolf, G. Cordoyiannis, C. Glorieux, J. Thoen, Phys. Rev. E 76, 051702 (2007).
K.P. Sigdel, G.S. Iannacchione, Phys. Rev. E 82, 051702 (2010).
H. Heuer, H. Kneppe, F. Schneider, Ber. Bunsenges. Phys. Chem. 93, 923 (1989).
Y. Yamaoka, Y. Taniguchi, S. Yasuzuka, Y. Yamamura, K. Saito, J. Chem. Phys. 135, 044705 (2011).
M.E. Fisher, Phys. Rev. 176, 257 (1968).
M.B. Sied, J. Salud, D.O. López, H. Allouchi, S. DDíez, J. Phys. Chem. B 107, 7820 (2003).
J. Thoen, in Heat Capacities: Liquids, Solutions and Vapours (The royal Society of Chemistry, London, 2010) Chapt. 13.
J.N. Murrel, E.A. Boucher, Properties of Liquids and Solutions (Wiley, New York, 1982) Chapt. 6.
A. Yethiraj, R. Mukhopadhyay, J. Bechhoefer, Phys. Rev. E 65, 021702 (2002).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Tripathi, C.S.P., Losada-Pérez, P., Leys, J. et al. Evidence from adiabatic scanning calorimetry for the Halperin-Lubensky-Ma effect at the N-SmA phase transitions in mixtures of 7OCB+heptane with an injected SmA phase. Eur. Phys. J. E 35, 54 (2012). https://doi.org/10.1140/epje/i2012-12054-5
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1140/epje/i2012-12054-5