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Related papers: Nanostructure of edge dislocations in a smectic C*…

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Chiral twisting of the molecular orientation within the layer of a smectic-A liquid crystal has been investigated using circular dichroism spectroscopy. The results indicate that a rotation of the layers away from the alignment direction is…

Soft Condensed Matter · Physics 2009-10-31 M. S. Spector , S. K. Prasad , B. T. Weslowski , R. D. Kamien , J. V. Selinger , B. R. Ratna , R. Shashidar

Dislocation core properties of tin (\beta-Sn) were investigated using the semi-discrete variational Peierls-Nabarro model (SVPN). The SVPN model, which connects the continuum elasticity treatment of the long-range strain field around a…

Materials Science · Physics 2017-03-08 M. A. Bhatia , M. Azarnoush , I. Adlakha , G. Lu , K. N. Solanki

Lattices with a basis can host crystallographic defects which share the same topological charge (e.g.~the Burgers vector $\vec b$ of a dislocation) but differ in their microscopic structure of the core. We demonstrate that in insulators…

Mesoscale and Nanoscale Physics · Physics 2014-06-03 Fernando de Juan , Andreas Rüegg , Dung-Hai Lee

Local electronic properties of quasi-two-dimensional Pb(111) islands with screw dislocations of different types on their surfaces were experimentally studied by means of low-temperature scanning tunneling microscopy and spectroscopy in the…

Mesoscale and Nanoscale Physics · Physics 2022-12-06 A. Yu. Aladyshkin , A. S. Aladyshkina , S. I. Bozhko

In this paper, we deduce a macroscopic strain gradient theory for plasticity from a model of discrete dislocations. We restrict our analysis to the case of a cylindrical symmetry for the crystal in exam, so that the mathematical formulation…

Mathematical Physics · Physics 2008-08-19 Adriana Garroni , Giovanni Leoni , Marcello Ponsiglione

The microscopic mechanism by which amorphous solids yield plastically under an externally applied stress or deformation has remained elusive in spite of enormous research activity in recent years. Most approaches have attempted to identify…

Soft Condensed Matter · Physics 2021-07-07 Matteo Baggioli , Ivan Kriuchevskyi , Timothy W. Sirk , Alessio Zaccone

Dislocations in soft condensed matter systems such as lamellar systems of polymers, liquid crystals and ternary mixtures of oil, water and surfactant (amphiphilic systems) are described in the framework of continuum elastic theory. These…

Condensed Matter · Physics 2015-06-25 R. Holyst , P. Oswald

Disclination lines in nematic liquid crystals can exist in different geometric conformations, characterised by their director profile. In certain confined, colloidal and even more prominently in chiral nematics, the director profile may…

Soft Condensed Matter · Physics 2015-06-12 Simon Čopar , Slobodan Žumer

We investigate the effects of topological defects (dislocations) to the ground state of the solid-on-solid (SOS) model on a simple cubic disordered substrate utilizing the min-cost-flow algorithm from combinatorial optimization. The…

Disordered Systems and Neural Networks · Physics 2009-10-31 Frank O. Pfeiffer , Heiko Rieger

We isolate single Schallamach waves --- detachment fronts that mediate inhomogeneous sliding between an elastomer and a hard surface --- to study their creation and dynamics. Based on measurements of surface displacement using high-speed…

Materials Science · Physics 2016-11-25 Koushik Viswanathan , Anirban Mahato , Srinivasan Chandrasekar

The smectic C (smC) phase represents a unique class of liquid crystal phases characterised by the layered arrangement of molecules with tilted orientations with respect to layer normals. Building upon the real-valued tensorial smectic A…

Soft Condensed Matter · Physics 2024-08-09 Jingmin Xia , Yucen Han

We present an experimental study of the surface effects (interactions with the container walls) during the nucleation and growth of smectic B crystals from the nematic in free growth and directional solidification of a mesogenic molecule…

Soft Condensed Matter · Physics 2015-06-24 T. Borzsonyi , S. Akamatsu

We use the phase field crystal model to study nucleation of edge dislocations in two dimensions under an applied stress field. A dislocation dipole nucleates under the applied stress, consistent with Burgers vector conservation. The phase…

Materials Science · Physics 2021-01-20 Vidar Skogvoll , Audun Skaugen , Luiza Angheluta , Jorge Viñals

The electric field applied perpendicularly to smectic layers breaks the rotational symmetry of the system. Consequently, the elastic energy associated with distortions induced by an edge dislocation diverges logarithmically with the size of…

Condensed Matter · Physics 2009-10-28 R. Holyst , P. Oswald

The Burgers distortion is a two-stage transition between body centered cubic (BCC) and hexagonal close-packed (HCP) structures. Refractory metal elements from the Sc and Ti columns of the periodic table (BCC/HCP elements) form BCC…

Materials Science · Physics 2018-11-28 Bojun Feng , Michael Widom

The influence of magnetism on the properties of screw dislocations in body-centered cubic chromium is investigated by means of ab initio calculations. Screw dislocations having Burgers vectors 1/2 111 and 100 are considered, following…

Materials Science · Physics 2021-05-21 Baptiste Bienvenu , Chu Fu , Emmanuel Clouet

We present a combined study by Scanning Tunneling Microscopy and atomistic simulations of the emission of dissociated dislocation loops by nanoindentation on a (001) fcc surface. The latter consist of two stacking-fault ribbons bounded by…

(a+c) dislocations in hexagonal materials are typically observed to be dissociated into partial dislocations. Edge (a+c) dislocations are introduced into (0001) nitride semiconductor layers by the process of plastic relaxation. As there is…

Applied Physics · Physics 2023-10-19 J. Smalc-Koziorowska , J. Moneta , G. Muziol , W. Chrominski , R. Kernke , M. Albrecht , T. Schulz , I. Belabbas

Understanding nanoscale mechanisms responsible for the recently discovered ferroelectric nematics can be helped by direct visualization of self-assembly of strongly polar molecules. Here we report on scanning tunneling microscopy (STM)…

We focus on existence and rigidity problems of the vectorial Peierls-Nabarro (PN) model for dislocations. Under the assumption that the misfit potential on the slip plane only depends on the shear displacement along the Burgers vector, a…

Analysis of PDEs · Mathematics 2022-11-08 Yuan Gao , Jian-Guo Liu , Zibu Liu