Scattering of gases from aligned liquid crystals: Collision-induced loss of order at the gas–liquid interface

Randall, Karen L.; Fan, Y. B.; Michel, Oliver; Goh, M. Cynthia; Donaldson, D. J.
December 1996
Journal of Chemical Physics;12/1/1996, Vol. 105 Issue 21, p9574
Academic Journal
An atomic beam of helium is scattered from the surface of an aligned nematic liquid crystal film (4′-pentyl-4-cyanbo biphenyl, 5CB). Collisions of atoms with the surface initiate a transient loss of order in the film. The magnitude of this change depends on the momentum direction of the atomic beam with respect to the liquid crystal alignment director. The effect is significantly more pronounced when the incoming beam is perpendicular to the director than when it is parallel. This anisotropy may be due to a more efficient alignment-changing torque exerted on the 5CB molecules by perpendicular collisions with He. © 1996 American Institute of Physics.


Related Articles

  • Multichannel analysis of He*(21S)+Ne elastic and inelastic scattering in crossed atomic beams. Martin, D. W.; Fukuyama, T.; Siska, P. E. // Journal of Chemical Physics;5/15/1990, Vol. 92 Issue 10, p5963 

    State-to-state elastic and inelastic angular distribution and time-of-flight measurements are reported for the scattering of He*(21S) by Ne in crossed supersonic atom beams at four collision energies in the range 0.6–2.8 kcal/mol. The inelastic collision products He+Ne*(nl), where...

  • Quantum-mechanical scattering of an atom from a rigid hemisphere on a flat surface. Choi, B.H.; Tang, K.T.; Toennies, J.P. // Journal of Chemical Physics;12/8/1997, Vol. 107 Issue 22, p9437 

    Discusses the formulation of the scattering of a monoenergetic beam of atoms by a hard hemisphere on a hard flat surface. Differential and integral cross sections calculated; Types of interference processes; Finding of Rayleigh oscillations in the integral cross section.

  • Inelastic scattering of atoms and molecules from liquid crystal surfaces. Waclawik, E.R.; Goh, M. Cynthia; Donaldson, D.J. // Journal of Chemical Physics;4/22/1999, Vol. 110 Issue 16, p8098 

    Collisions of an atomic beam of He atoms with the surface of an aligned nematic liquid crystal film (4′-pentyl-4-cyano biphenyl, 5CB) initiate a transient change in the aligmnent of the surface region of the film. The effect is greater when the He atoms approach perpendicular to the...

  • New liquid crystal display with bistability and selective erasure using scattering in filled.... Kreuzer, M.; Tschudi, T.; Eidenschink, R. // Applied Physics Letters;4/12/1993, Vol. 62 Issue 15, p1712 

    Examines the bistable scattering effect in a filled nematic liquid crystal. Application of the liquid crystal to a high resolution laser-addressed display; Characteristics of the filled nematic liquid crystal; Use of filled nematic liquid crystal in obtaining a scattering liquid crystal.

  • Scattering from mixtures of flexible and stiff polymers. Hammouda, Boualem // Journal of Chemical Physics;2/15/1993, Vol. 98 Issue 4, p3439 

    The random phase approximation (RPA) is used to calculate the scattering function for multicomponent mixtures of flexible and stiff polymers. These calculations will be useful for the qualitative interpretation of small angle neutron scattering (SANS) data from binary mixtures of polymer liquid...

  • A neutron scattering study of orientational ordering in the smectic and nematic phases of the liquid crystal, 2[sup ′],3[sup ′]-difluoro-4-heptyl-4[sup ″]-nonyl p-terphenyl. Hamley, I. W.; Luckhurst, G. R.; Richardson, R. M.; Santos, F. // Journal of Chemical Physics;3/1/2002, Vol. 116 Issue 9, p3887 

    The orientational order parameters &Pmarc;[sub 2], &Pmarc;[sub 4], and &Pmarc;[sub 6] have been determined by neutron scattering from a mixture of normal hydrogenous and deuterium labeled molecules in the nematic, smectic A and smectic C phases of the mesogen...

  • Smectic ordering in confined liquid crystal films: A depth study. Martı´nez-Miranda, L. J. // Journal of Applied Physics;5/15/2002 Part 1, 2 & 3, Vol. 91 Issue 10, p6452 

    Grazing incidence x-ray scattering was used to study the structure of films of a room temperature smectic-C[sup *] mixture, deposited on glass substrates, that consisted of gratings with a 9 µm period. There is evidence for the presence of two regions of confinement as function of film...

  • Filled liquid crystal depolarizers. Diorio, Nicholas J.; Fisch, Michael R.; West, John L. // Journal of Applied Physics;10/15/2001, Vol. 90 Issue 8, p3675 

    The construction and properties of scattering type liquid crystal depolarizers are discussed. The Mueller matrices that describe these devices are measured and compared to ideal depolarizers and ideal linear materials. The present depolarizers do not perform as well as crystal...

  • Micrometer-sized nozzles and skimmers for the production of supersonic He atom beams. Braun, J.; Day, P.K.; Toennies, J.P.; Witte, G. // Review of Scientific Instruments;Aug1997, Vol. 68 Issue 8, p3001 

    Describes micrometer-sized nozzles and skimmers made from drawn glass tubes and their production of highly monoenergetic helium atom beams. Measured speed ratios of the intense beams provided by the glass nozzles; Reduction of the size of helium-atom surface-scattering time-of-flight...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics