Ringlike cores of cylindrically confined nematic point defects

De Luca, Gino; Rey, Alejandro D.
March 2007
Journal of Chemical Physics;3/7/2007, Vol. 126 Issue 9, p094907
Academic Journal
Nematic liquid crystals confined in a cylindrical capillary and subjected to strong homeotropic anchoring conditions is a long-studied fundamental problem that uniquely incorporates nonlinearity, topological stability, defects, and texture physics. The observed and predicted textures that continue to be investigated include escape radial, radial with a line defect, planar polar with two line defects, and periodic array of point defects. This paper presents theory and multiscale simulations of global and fine scale textures of nematic point defects, based on the Landau–de Gennes tensor order parameter equations. The aim of this paper is to further investigate the ringlike nature of point defect cores and its importance on texture transformation mechanisms and stability. The paper shows that the ringlike cores can be oriented either along the cylinder axis or along the radial direction. Axial rings can partially expand but are constrained by the capillary sidewalls. Radial rings can deform into elliptical structures whose major axis is along the capillary axis. The transformation between several families of textures under capillary confinement as well as their stability is discussed in terms of defect ring distortions. A unified view of nematic textures found in the cylindrical cavities is provided.


Related Articles

  • The Energy of Radial and Hyperbolic Defects in a Long Cylindrical Capillary. Pershin, V. K.; Kouchnareva, T. V. // Crystallography Reports;Mar2000, Vol. 45 Issue 2, p310 

    Studies the formation of unit point defects and formed due to two-sided escape of the disclination in circular cylindrical capillary under the normal boundary conditions. Calculation and analysis of the results for a thin long cylindrical capillary; Energy of point defects formed as a...

  • Point defects and ring defects in a nematic liquid crystal in a cylindrical capillary. Pershin, V. K.; Klebanov, I. I.; Zalmanov, P. B. // Technical Physics;Jul99, Vol. 44 Issue 7, p763 

    The bidirectional escape into the third dimension of a linear disclination of strength m=1(L[sub +1][sup p]) in a cylindrical capillary with normal boundary conditions is investigated. It is shown that in this case two types of defects arise in the capillary: point defects and ring defects, each...

  • Defects in liquid crystals. Brinkman, William F.; Cladis, Patricia E. // Physics Today;May82, Vol. 35 Issue 5, p48 

    Discusses the defects of liquid crystals at different phases. Characteristics of nematic phase defects; Topological analysis; Basis of the arguments for describing smectic-A defects.

  • Fast Q-tensor method for modeling liquid crystal director configurations with defects. Lee, Gi-Dong; Anderson, James; Bos, Philip J. // Applied Physics Letters;11/18/2002, Vol. 81 Issue 21, p3951 

    A fast Q-tensor method, which can model the configuration of the liquid crystal director fields containing defects, is proposed. Conceptually based on the Oseen–Frank approach, we have added temperature energy density terms in addition to the strain energy term. We have also derived an...

  • Comprehensive insights into point defect and defect cluster formation in CuInSe2. Stephan, Christiane; Schorr, Susan; Tovar, Michael; Schock, Hans-Werner // Applied Physics Letters;2/28/2011, Vol. 98 Issue 9, p091906 

    The concentration of native point defects in CuInSe2 powder material as a function of stoichiometry has been experimentally determined by neutron powder diffraction. A correlation between the Cu/In ratio and the density of VCu as well as InCu has been established and their concentrations are...

  • Silicon two-dimensional phononic crystal resonators using alternate defects. Wang, Nan; Hsiao, Fu-Li; Palaniapan, Moorthi; Lee, Chengkuo // Applied Physics Letters;12/5/2011, Vol. 99 Issue 23, p234102 

    We present the numerical and experimental investigations of micromechanical resonators made by creating alternate defects with different central-hole radii (r′) in a two-dimensional (2-D) phononic crystal (PnC) slab. The PnC structures were fabricated by etching a square array of...

  • Composition dependent phase transformation of Pt0.5− xMn0.5+ x from A1 to L10 phase. Ji, C.-X.; Huang, M. L.; Kramer, M. J.; Zhang, C.; Wu, K. S.; Yang, Y.; Chang, Y. A. // Applied Physics A: Materials Science & Processing;May2010, Vol. 99 Issue 2, p471 

    Pt0.5− xMn0.5+ x films were prepared by sputtering deposition of Pt foil and Mn target to study the order-disorder transition from a thermodynamic metastable fcc (A1) phase to L10 phase. Both Differential Scanning Calorimetry and High Temperature X-Ray Diffraction studies showed the phase...

  • Spiral Patterns of Dislocations at Nodes in (111) Semi-coherent FCC Interfaces. Shuai Shao; Jian Wang; Amit Misra; Hoagland, Richard G. // Scientific Reports;8/16/2013, p1 

    In semi-coherent interface, a superposed network of interface dislocations accommodates the attendant coherency strains in the adjacent crystals and their intersections (referred to as nodes) can act as sinks and sources for point defects because of the low formation energy. Nodes in {111}...

  • Enhancement of flux pinning and critical currents in YBa2Cu3O7-δ films by nanoscale iridium pretreatment of substrate surfaces. Aytug, T.; Paranthaman, M.; Gapud, A. A.; Kang, S.; Christen, H. M.; Leonard, K. J.; Martin, P. M.; Thompson, J. R.; Christen, D. K.; Meng, R.; Rusakova, I.; Chu, C. W.; Johansen, T. H. // Journal of Applied Physics;12/1/2005, Vol. 98 Issue 11, p114309 

    We have acquired positive results in a controlled study to investigate the effects of substrate surface modification on the growth-induced flux-pinning nanostructures in YBa2Cu3O7-δ (YBCO) films. Nanoscale iridium (Ir) particles were applied to single-crystal SrTiO3 substrate surfaces using...


Read the Article


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

Try another library?
Sign out of this library

Other Topics