Electroconvection in a Freely Suspended Film of Smectic a Liquid Crystal

  • Stephen W. Morris
  • John R. de Bruyn
  • A. D. May
Part of the NATO ASI Series book series (NSSB, volume 225)


Liquid crystals in the smectic A phase have a layered structure [1]. They are liquid—like in the plane of the layers, but act like a soft solid in the perpendicular direction. A film of smectic A, supported only at its edges, forms a nearly two—dimensional liquid [2]. We observe that such a film can be driven into convection by an electric field applied in the plane of the film [3]. Two types of convection are observed; one which requires the injection of charge at the electrodes [4,5] and one which is due to charged impurities already present in the material [6,7]. The director orientation is unaffected by the motion of the liquid. In contrast to the behaviour of nematic or isotropic films [8,9], we find that the free surfaces of the smectic are not deformed by the flow. No significant hysteresis is observed at the bifurcation to the convecting state. The flow patterns, shown if Fig. 1, resemble two-dimensional versions of conventional convection rolls. This instability is an interesting new example of a low dimensional pattern-forming system [10].


Liquid Crystal Critical Voltage Critical Amplitude Charged Impurity Roll Pattern 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [1]
    L. M. Blinov, Electro-optical and Magneto-optical Properties of Liquid Crystals, Wiley, NY, (1983).Google Scholar
  2. [2]
    R. Pindak and D. Moncton, Phys. Today, 35(5), 57 (1982).ADSCrossRefGoogle Scholar
  3. [3]
    S. W. Morris, J. R. de Bruyn and A. D. May, submitted to Physical Review.Google Scholar
  4. [4]
    N. J. Felici, J. Phys. (Paris), 37, C1–117, (1979).Google Scholar
  5. [5]
    J. C. LaCroix, P. Atten and E. J. Hopfinger, J. Fluid Mech., 69, 539, (1975).ADSzbMATHCrossRefGoogle Scholar
  6. [6]
    M. I. Barnik, L. M. Blinov, S. A. Pikin and A. N. Trufanov, Sov. Phys. JETP, 45, 396, (1977).ADSGoogle Scholar
  7. [7]
    P. Atten, B. Malraison and S. Ali Kani, J. Electrost., 12, 477, (1982).CrossRefGoogle Scholar
  8. [8]
    S. Faetti, L. Fronzoni and P. A. Rolla, J. Chem. Phys., 79, 5054, (1983).ADSCrossRefGoogle Scholar
  9. [9]
    S. Faetti, L. Fronzoni and P. A. Rolla, J. Phys. (Paris), 40, C3–497, (1979).Google Scholar
  10. [10]
    G. Ahlers, Complex Systems, Vol 7, Santa Fe Institute Studies in the Sciences of Complexity, ed. Dan Stein, Addison, Reading Mass., (1989).Google Scholar
  11. [11]
    R. Cocco, F. Gaspard and R. Herino, J. de Chim. Phys., 76, 383, (1979).Google Scholar
  12. [12]
    C. Rosenblatt and N. M. Amer, Appl. Phys. Lett., 36, 432, (1980).ADSCrossRefGoogle Scholar
  13. [13]
    M. Nakagawa and T. Akahane, J. Phys. Soc. Jpn., 52, 3773, (1983)ADSCrossRefGoogle Scholar
  14. [13a]
    M. Nakagawa and T. Akahane, J. Phys. Soc. Jpn., 52, 3782, (1983).ADSCrossRefGoogle Scholar
  15. [14]
    R. J. Turnbull, J. Phys. D, 6, 1745, (1973).ADSCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1990

Authors and Affiliations

  • Stephen W. Morris
    • 1
  • John R. de Bruyn
    • 2
  • A. D. May
    • 1
    • 3
  1. 1.Department of PhysicsUniversity of TorontoTorontoCanada
  2. 2.Department of PhysicsMemorial University of NewfoundlandSt. John’sCanada
  3. 3.Ontario Laser and Lightwave Research CentreTorontoCanada

Personalised recommendations