Abstract
Macroporous silicon with deep regular channels 3–4.5 µm in diameter was infiltrated with discotic and ferroelectric liquid crystals (LCs) at the temperature of the isotropic phase, and then, the system was slowly cooled to room temperature, with the liquid crystalline mesophase formed. The orientation of the LC molecules in the porous matrix was studied by FTIR spectroscopy. The alignment of LCs was ascertained by comparing the behavior of various vibrational bands of a liquid crystal introduced into the porous matrix with that for LC inside the bulk cells of planar and homeotropic alignment. The molecules of the discotic LC show a planar orientation of their column’s axis with respect to the surface of the macroporous silicon wafer; i.e., they are perpendicular to the channel axis. The long molecular axis of the ferroelectric LC is aligned with the pore walls, having homeotropic orientation with respect to the wafer surface. In a macroporous silicon matrix, both kinds of LCs show unexpected enhancement of the low-frequency vibrational bands.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
T. Bellini, N. A. Clark, C. D. Muzny, et al., Phys. Rev. Lett. 69(5), 788 (1992).
N. A. Clark, T. Bellini, R. M. Malzbender, et al., Phys. Rev. Lett. 71(21), 3505 (1993).
G. S. Iannacchione, G. P. Crawford, S. Zumer, et al., Phys. Rev. Lett. 71(16), 2595 (1993).
H. Xu, J. K. Vij, A. Rappaport, and N. Clark, Phys. Rev. Lett. 79(2), 249 (1997).
P. Ziherl, A. Sarlah, and S. Zumer, Phys. Rev. E 58(1), 602 (1998).
P. Ziherl and S. Zumer, Phys. Rev. Lett. 78(4), 682 (1997).
T. S. Perova, J. K. Vij, and A. Kocot, Adv. Chem. Phys. 113, 341 (2000).
A. Kocot, J. K. Vij, and T. S. Perova, Adv. Chem. Phys. 113, 203 (2000).
O. Bisi, S. Ossicino, and L. Pavesi, Surf. Sci. Rep. 38(1–3), 1 (2000).
U. Gruning and V. Lehmann, Appl. Phys. Lett. 68(6), 747 (1996).
A. Chelnokov, K. Wang, S. Rowson, et al., Appl. Phys. Lett. 77(19), 2943 (2000).
S. W. Leonard, J. P. Mondia, H. M. van Driel, et al., Phys. Rev. B 61(4), R2389 (2000).
M. Thonissen, M. Marso, R. Arens-Fisher, et al., J. Porous Mater. 7(1/3), 205 (2000).
S. Kumar, M. Manickam, V. S. K. Balagurusamy, and H. Schonherr, Liq. Cryst. 26(10), 1455 (1999).
V. Lehmann and H. Foll, J. Electrochem. Soc. 137(2), 653 (1990).
N. M. Shtykov, J. K. Vij, M. I. Barnik, and H. T. Nguyen, Kristallografiya 45(4), 745 (2000) [Crystallogr. Rep. 45, 682 (2000)].
H. Binder, H. Schmiedel, G. Lantzsch, et al., Liq. Cryst. 21(3), 415 (1996).
M. V. Wolkin, S. Chan, and P. M. Fauchet, Phys. Status Solidi A 182(1), 573 (2000).
A. Sonin, The Surface Physics of Liquid Crystals (Gordon & Breach, Amsterdam, 1995).
E. V. Alieva, L. A. Kuzik, G. Mattei, et al., Phys. Status Solidi A 175(1), 115 (1999).
A. M. Zheltikov, Usp. Fiz. Nauk 170(11), 1203 (2000).
Author information
Authors and Affiliations
Additional information
From Fizika Tverdogo Tela, Vol. 44, No. 6, 2002, pp. 1145–1150.
Original English Text Copyright © 2002 by Perova, Astrova, Tsvetkov, Tkachenko, Vij, Kumar.
This article was submitted by the authors in English.
Rights and permissions
About this article
Cite this article
Perova, T.S., Astrova, E.V., Tsvetkov, S.E. et al. Orientation of discotic and ferroelectric liquid crystals in a macroporous silicon matrix. Phys. Solid State 44, 1196–1202 (2002). https://doi.org/10.1134/1.1485052
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1134/1.1485052