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10 results on '"Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)"'

1. Contact angle dynamics on pseudo-brushes: Effects of polymer chain length and wetting liquid

Author

Kristina Davitt, Romain Lhermerout, Laboratoire de Physique des Solides (LPS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique Statistique de l'ENS (LPS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Mécanique, Matière Molle, Morphogénèse, Laboratoire de physique de l'ENS - ENS Paris (LPENS (UMR_8023)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Université Paris Diderot - Paris 7 (UPD7)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Université Paris Diderot - Paris 7 (UPD7)

Subjects
polymer brush, viscoelastic dissipation, Materials science, contact angle hysteresis, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Viscoelasticity, Physics::Fluid Dynamics, Contact angle, chemistry.chemical_compound, Colloid and Surface Chemistry, Wetting dynamics, Composite material, chemistry.chemical_classification, Polydimethylsiloxane, Polymer, Dissipation, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Condensed Matter::Soft Condensed Matter, Hysteresis, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Polymerization, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Wetting, 0210 nano-technology
Abstract

International audience; In this study we investigate the exceptional wetting properties of thin polymer layers. Here the polymer is deposited in the form of a polydimethylsiloxane (PDMS) pseudo-brush and contact line dynamics are measured for both varying polymerization index and nature of the partially-wetting liquid. We use a custom-built experimental apparatus to explore wetting dynamics over 7 decades of velocity, with a precision of 0.01 • in variations of the contact angle. We show that the presence of a pseudo-brush can result in a remarkably small contact angle hysteresis as well as the appearance of an additional source of dissipation and that these two phenomena depend on the chain length and the wetting liquid. Qualitatively, we interpret these findings as the ability of the layer to behave as a liquid-like interface, and quantitatively by using a simple model of viscoelastic dissipation in soft thin films.

Published
2019

2. Quasipatterns versus superlattices resulting from the superposition of two hexagonal patterns

Author

Stéphan Fauve, Gérard Iooss, Laboratoire de Physique Statistique de l'ENS (LPS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Physique Non-Linéaire, Laboratoire de physique de l'ENS - ENS Paris (LPENS (UMR_8023)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Université Paris Diderot - Paris 7 (UPD7)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Université Paris Diderot - Paris 7 (UPD7), Institut Universitaire de France (IUF), and Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.)

Subjects
Strategy and Management, Superlattice, [MATH.MATH-DS]Mathematics [math]/Dynamical Systems [math.DS], Asymptotic expansion, 02 engineering and technology, Instability, law.invention, Bifurcations, Superposition principle, [NLIN.NLIN-PS]Nonlinear Sciences [physics]/Pattern Formation and Solitons [nlin.PS], 0203 mechanical engineering, law, Quantum mechanics, Media Technology, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], General Materials Science, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Faraday cage, Nonlinear Sciences::Pattern Formation and Solitons, Marketing, Physics, Forcing (recursion theory), Hexagonal crystal system, Quasicrystal, 35B32, 35C20, 52C23, 37S40, Nonlinear effects, 020303 mechanical engineering & transports, quasicrystals
Abstract

International audience; We present a short review of the experimental observations and mechanisms related to the generation of quasipatterns and superlattices by the Faraday instability with two-frequency forcing. We show how two frequency forcing makes possible triad interactions that generate hexagonal patterns, twelvefold quasipatterns or superlattices that consists of two hexagonal patterns rotated by an angle α relative to each other. We then consider which patterns could be observed when α does not belong to the set of prescribed values that give rise to periodic superlattices. Using the Swift-Hohenberg equation as a model, we find that quasipattern solutions exist for nearly all values of α . However, these quasipatterns have not been observed in experiments with the Faraday instability for α 6 = π/ 6. We discuss possible reasons and mention a simpler framework that could give some hint about this problem.; Nous présentons une courte revue des observations expérimentales et des mécanismes qui ont permis d'engendrer des structures quasi-cristallines à l'aide de l'instabilité de Faraday sous l'effet d'une excitation périodique comportant deux fréquences. Nous montrons comment l'excitation à excitation`excitation à deux fréquences permet d'obtenir des triades de vecteurs d'onde résonantes qui induisent la formation de structures hexagonales, de structures quasi-cristallines dodécagonales ou de super-réseaux résultant de la superposition de deux réseaux d'hexagones tournés l'un par rapport à rapport`rapport à l'autre d'un angle α. Nous considérons ensuite quelles sont les structures obtenues lorsque α ne prend pas la série de valeurs discrètes conduisant à conduisant`conduisant à un super-réseau périodique. Nous montrons sur l'´ équation de Swift-Hohenberg qu'il existe dans ce cas des solutions à solutions`solutions à symétrie quasi-cristalline pour presque toutes les valeurs de α. Nous discutons les raisons possibles pour lesquelles ces solutions n'ont pas été observées expérimentalement pour α = π/6 et nous mentionnons un cadre plus simple qui permettrait d'éclaircir cette question.

Published
2019

3. Protein Crowding Is a Determinant of Lipid Droplet Protein Composition

Author

Nora Kory, Abdou-Rachid Thiam, Tobias C. Walther, Robert V. Farese, Laboratoire de Physique Statistique de l'ENS (LPS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Lipolysis, [SDV]Life Sciences [q-bio], Plasma protein binding, Article, General Biochemistry, Genetics and Molecular Biology, Cell Line, Lipid droplet, Organelle, Animals, Drosophila Proteins, Choline-Phosphate Cytidylyltransferase, Molecular Biology, ComputingMilieux_MISCELLANEOUS, biology, Lipid metabolism, Lipid Droplets, Cell Biology, Lipid Metabolism, biology.organism_classification, Protein subcellular localization prediction, Drosophila melanogaster, Biochemistry, Multiprotein Complexes, Glycerol-3-Phosphate O-Acyltransferase, Biophysics, Macromolecular crowding, Hydrophobic and Hydrophilic Interactions, Protein Binding, Developmental Biology
Abstract

SummaryLipid droplets (LDs) are lipid storage organelles that grow or shrink, depending on the availability of metabolic energy. Proteins recruited to LDs mediate many metabolic functions, including phosphatidylcholine and triglyceride synthesis. How the LD protein composition is tuned to the supply and demand for lipids remains unclear. We show that LDs, in contrast to other organelles, have limited capacity for protein binding. Consequently, macromolecular crowding plays a major role in determining LD protein composition. During lipolysis, when LDs and their surfaces shrink, some, but not all, proteins become displaced. In vitro studies show that macromolecular crowding, rather than changes in monolayer lipid composition, causes proteins to fall off the LD surface. As predicted by a crowding model, proteins compete for binding to the surfaces of LDs. Moreover, the LD binding affinity determines protein localization during lipolysis. Our findings identify protein crowding as an important principle in determining LD protein composition.

Published
2015
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4. How Diverse Retinal Functions Arise from Feedback at the First Visual Synapse

Author

Antonia Drinnenberg, Rava Azeredo da Silveira, Josephine Jüttner, Felix Franke, Andreas Hierlemann, Péter Hantz, Rei K. Morikawa, Daniel Hillier, Botond Roska, Friedrich Miescher Institute for Biomedical Research (FMI), Novartis Research Foundation, Department of Biosystems Science and Engineering [ETH Zürich] (D-BSSE), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Laboratoire de Physique Statistique de l'ENS (LPS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Princeton Neuroscience Institute [Princeton]

Subjects
Retinal Ganglion Cells, 0301 basic medicine, Retinal Bipolar Cells, Cell type, Interneuron, [SDV]Life Sciences [q-bio], Models, Neurological, Retinal Horizontal Cells, Biology, Feedback, Synapse, Mice, 03 medical and health sciences, chemistry.chemical_compound, Interneurons, medicine, Animals, Vision, Ocular, Retina, General Neuroscience, Retinal, Ganglion, Brain region, 030104 developmental biology, medicine.anatomical_structure, chemistry, Mouse Retina, Synapses, Calcium, Neuroscience, Photoreceptor Cells, Vertebrate
Abstract

International audience; Many brain regions contain local interneurons of distinct types. How does an interneuron type contribute to the input-output transformations of a given brain region? We addressed this question in the mouse retina by chemogenetically perturbing horizontal cells, an interneuron type providing feedback at the first visual synapse, while monitoring the light-driven spiking activity in thousands of ganglion cells, the retinal output neurons. We uncovered six reversible perturbation-induced effects in the response dynamics and response range of ganglion cells. The effects were enhancing or suppressive, occurred in different response epochs, and depended on the ganglion cell type. A computational model of the retinal circuitry reproduced all perturbation-induced effects and led us to assign specific functions to horizontal cells with respect to different ganglion cell types. Our combined experimental and theoretical work reveals how a single interneuron type can differentially shape the dynamical properties of distinct output channels of a brain region.

Published
2018

5. Thermal statistical ensembles of black holes

Author

Miguel D. Bustamante, Fabrice Debbasch, C. Chevalier, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Statistique de l'ENS (LPS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Statistics and Probability, Physics, Astrophysics::High Energy Astrophysical Phenomena, White hole, Fuzzball, Condensed Matter Physics, Black hole, General Relativity and Quantum Cosmology, Micro black hole, Theoretical physics, Classical mechanics, Binary black hole, Nonsingular black hole models, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Black hole thermodynamics, Hawking radiation
Abstract

ERGA/LERMA Universite Paris VI UMR 8112, 3 rue Galil´ ´ee 94200 Ivry, FranceAbstractWe consider statistical ensembles of Schwarzschild black holes and prove that theseensembles describe black holes of non vanishing temperatures. The mean space-times as-sociated to these ensembles are explored through exact computations of their energy distri-butions, total masses and calorific capacities. We discuss our results, with special emphasison their connections with current and near future observations of astrophysical black holes,string theory and cosmology.Key words: Relativistic statistical physics, black holes.

Published
2007

6. Coherent dynamics of microcavity polaritons in the nonlinear regime

Author

R. Romestain, D. Le Si Dang, Claude Delalande, Ph. Roussignol, Régis André, A. Huynh, Jérôme Tignon, Laboratoire Pierre Aigrain (LPA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics::Optics, 01 natural sciences, 010305 fluids & plasmas, symbols.namesake, Four-wave mixing, Pauli exclusion principle, Quantum mechanics, 0103 physical sciences, Polariton, Coulomb, 010306 general physics, ComputingMilieux_MISCELLANEOUS, Mixing (physics), [PHYS]Physics [physics], Physics, Condensed Matter::Other, business.industry, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Nonlinear system, Semiconductor, Quantum electrodynamics, symbols, Transient (oscillation), business
Abstract

We report an experimental study of polariton coherent dynamics in II–VI semiconductor microcavities in the nonperturbative regime, using transient four-wave mixing. By comparison with model calculations based on the resolution of Bloch–Maxwell equations, we show that Pauli blocking and Coulomb interactions induce different coherent dynamics. We deduce a method to determine experimentally the nature of intrinsic nonlinearities in semiconductor microcavities. In particular, we show that upper and lower polariton modes experience distinct nonlinear dynamics.

Published
2002

7. Self-organization on Au(111) vicinal surfaces and the role of surface stress

Author

Pascal Hecquet, J. Lecoeur, F. Pourmir, J. Klein, Jean-Marc Berroir, B. Salanon, Sylvie Rousset, Laboratoire Pierre Aigrain (LPA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Morphology (linguistics), spatial self-organization, 02 engineering and technology, 01 natural sciences, law.invention, Transition metal, law, 0103 physical sciences, Materials Chemistry, Facet, 010306 general physics, surface stress, [PHYS]Physics [physics], low energy electron diffraction, Range (particle radiation), Low-energy electron diffraction, Condensed matter physics, Au(111) vicinal surfaces, Chemistry, Surface stress, Surfaces and Interfaces, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Surfaces, Coatings and Films, Crystallography, scanning tunneling microscopy, Scanning tunneling microscope, 0210 nano-technology, Vicinal
Abstract

Using scanning tunneling microscopy and low energy electron diffraction, we report on the long range spatial self-organization of four Au(lll) vicinal surfaces. It is shown that the atomic structure of steps strongly affects the long range ordered morphology: periods on surfaces misoriented towards the [2 (1) over bar (1) over bar] azimuthal direction are about 100 A; whereas quasi-periods are about 2000 Angstrom when surfaces are misoriented towards the opposite azimuth. The stable structures are explained in terms of stress relief induced at the facet edges. (C) 1999 Published by Elsevier Science B.V. All rights reserved.

Published
1999

8. LEED study of activated nitrogen adsorption on (100) and (h11) faces of copper

Author

Sylvie Rousset, F. Pourmir, S. Gauthier, J. Klein, M. Sotto, Laboratoire Pierre Aigrain (LPA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
chemistry.chemical_element, 02 engineering and technology, Nitride, Epitaxy, 01 natural sciences, nitrogen, Overlayer, Transition metal, low energy electron diffraction (LEED), 0103 physical sciences, Materials Chemistry, Surface layer, 010306 general physics, [PHYS]Physics [physics], geography, geography.geographical_feature_category, Surfaces and Interfaces, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Copper, Surfaces, Coatings and Films, Faceting, Crystallography, Terrace (geology), chemistry, copper, 0210 nano-technology
Abstract

LEED observations on nitrogen adsorbed on (h11) stepped and (100) copper faces have shown the existence of two surface phases with a first order transition. The first one corresponds, on the (100) face, to the formation of an ordered stepped overlayer composed of alternating square c(2 × 2)N island and bare copper of 〈100〉 atomic rows and on the (h11) stepped faces, to an unusual nitrogen induced faceting into (100) and (h′11) facets: the terrace width of these (h′11) facets decreases with coverages and a (h11) stepped face (h = 65 ± 4) with large (100) terrace widths is observed. The second phase, in the ultimate state of adsorption might correspond to the formation of a copper nitride surface layer in epitaxy on all the copper faces under investigation.

Published
1997

9. An STM study of the adsorption of Pb on Cu(100): formation of an ordered surface alloy

Author

F. Bocquet, Sylvie Rousset, S. Robert, J.L. Duvault, J. Klein, Sébastien Gauthier, Knoop, Martina, Laboratoire Pierre Aigrain (LPA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
compound formation, Alloy, chemistry.chemical_element, 02 engineering and technology, engineering.material, Epitaxy, 01 natural sciences, [PHYS] Physics [physics], law.invention, Adsorption, alloys, Transition metal, law, 0103 physical sciences, Materials Chemistry, Surface layer, 010306 general physics, [PHYS]Physics [physics], lead, Superstructure, Chemistry, epitaxy, low index single crystal surfaces, Surfaces and Interfaces, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Copper, Surfaces, Coatings and Films, Crystallography, copper, engineering, scanning tunneling microscopy, Scanning tunneling microscope, 0210 nano-technology
Abstract

The adsorption of Pb on Cu(100) from 0 to 1 ML was investigated by UHV scanning tunneling microscopy. We obtained atomic resolution images of the different superstructures which appear at 300 K with increasing coverage (c(4 x 4), c(2 x 2) and c(5 root 2 x root 2)R45 degrees). We confirm recent results and propose, partly on the basis of low temperature studies, new arguments in favour of an incorporation of lead atoms in the surface layer of copper for low coverage. We demonstrate that the c(4 x 4) superstructure corresponds to an ordered surface alloy of Pb3Cu4 composition, by investigating separately the alloying and de-alloying transitions. De-alloying occurs during the first-order transition between the c(4 x 4) and c(2 x 2) superstructures.

Published
1996

10. Superperiodicity in the thermal faceting of Au(111) vicinal surfaces

Author

Jean-Paul Bellier, F. Pourmir, J. Lecoeur, Sylvie Rousset, Sébastien Gauthier, M. Sotto, J. Klein, Laboratoire Pierre Aigrain (LPA), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Thermodynamic equilibrium, Annealing (metallurgy), LOW ENERGY ELECTRON DIFFRACTION (LEED), 02 engineering and technology, 01 natural sciences, law.invention, Transition metal, FACETING, law, 0103 physical sciences, Materials Chemistry, SURFACE ENERGY, SURFACE THERMODYNAMICS, GOLD, 010306 general physics, [PHYS]Physics [physics], Low-energy electron diffraction, Chemistry, Surfaces and Interfaces, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Surface energy, Surfaces, Coatings and Films, Faceting, Crystallography, Chemical physics, Scanning tunneling microscope, SCANNING TUNNELING MICROSCOPY, 0210 nano-technology, VICINAL SINGLE CRYSTAL SURFACES, Vicinal, METALLIC SURFACES
Abstract

Using scanning tunneling microscopy and low energy electron diffraction, the thermal faceting of two Au(111) vicinal surfaces belonging to the [01 1 ] zone is investigated. Above 700 K, a final stable state is found: it consists of a periodic succession of (111) and (755) facets. The superperiod is 70 A for Au(1199) and 110 A for Au(433). The quantitative agreement between our results and the observations of macroscopic gold crystals strongly suggests that the novel periodic morphology is an equilibrium state. Possible origins to account for this morphology are discussed.

Published
1995

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