Publications associées à Loi de Bragg

Influence of ionization and cumulative effects on laser-induced crystallization in multilayer dielectrics

Yves Bellouard, Victor Carle Adrien Boureau, Ruben Ricca

Crystallization of amorphous layers has been demonstrated under various radically different laser-exposure conditions, including continuous wave (cw) and pulsed lasers. Here, we investigate the specific role of ionization in the crystallization of dielectr ...

2024

Scalable Room-Temperature Synthesis of a Hydrogen-Sieving Zeolitic Membrane on a Polymeric Support

Kumar Varoon Agrawal, Jian Hao, Xuekui Duan, Mostapha Dakhchoune

Thescalable synthesis of high-temperature H-2-sieving membranesfor energy-efficient carbon capture can potentiallyenable the implementation of precombustion carbon capture at a rapidpace. ...

AMER CHEMICAL SOC2023

Anomalous Hall effect and magnetic structure of the topological semimetal (Mn0.78Fe0.22)3Ge

Jian Rui Soh, Jan Persson

Me3+8Ge, being a Weyl semimetal, shows a large anomalous Hall effect (AHE), which decreases slowly with an increase in 8 from 0.1 to 0.4. However, AHE in this compound remains significantly large in the whole range of 8 because of the robust nature of the ...

AMER PHYSICAL SOC2023

Metasurface-stabilized optical microcavities

Ileana-Cristina Benea-Chelmus

Cavities concentrate light and enhance its interaction with matter. Confining to microscopic volumes is necessary for many applications but space constraints in such cavities limit the design freedom. Here we demonstrate stable optical microcavities by cou ...

Nature Portfolio2023

Direct Observation of the Phase Transition in C60 Fullerene

Chengcheng Yan

In the third study, the order-disorder phase transition of single-crystal C60 is studied using time-resolved electron microscopy. Solid C60 undergoes a first-order phase transition upon heating to 260 K. This is a structural transition from the low-tempera ...

EPFL Infoscience2023

An elementary treatment on the diffraction of crystalline structures

Gervais Chapuis

Although W. L. Bragg's law can be easily derived for beginners in the field of crystallography, its interpretation however seems to cause some difficulties which lies essentially in the relation between the concept of lattice planes and the unit cell const ...

2022

Concrete cancer : characterization of Alkali Silica Reaction early stage products by electron microscopy

Solène Anne-Lise Albinski

Concrete deterioration is a natural process, which has to be carefully monitored over a the service life of a structure. The Alkali-Silica Reaction (ASR) is a slow-process degradation, which devel-ops over decades and is therefore difficult to predict. Sin ...

EPFL2022

Chalcogenide glasses for innovation in applied science: fundamental issues and new insights

Assil Bouzid, Carlo Massobrio

We provide an overview of what has been accomplished by our team, since 1998, in the area of first-principles molecular dynamics (FPMD) modeling of glassy chalcogenides, a prototypical family of network-forming disordered materials. After a broad introduct ...

IOP PUBLISHING LTD2020

Long-range magnetic ordering in Li2MnGeO4 and precursor short-range spin correlations

Irina Safiulina, Artem Korshunov

Long-range magnetic ordering and short-range spin correlations in layered noncentrosymmetric orthogermanate Li2MnGeO4 were studied by means of polarized and unpolarized neutron scattering. The combined Rietveld refinement of synchrotron and neutron powder ...

2020

Characterizing crystalline defects in single nanoparticles from angular correlations of single-shot diffracted X-rays

Christoph Bostedt, Alessandro Colombo, Giorgio Rossi

Characterizing and controlling the uniformity of nanoparticles is crucial for their application in science and technology because crystalline defects in the nanoparticles strongly affect their unique properties. Recently, ultra-short and ultra-bright X-ray ...

INT UNION CRYSTALLOGRAPHY2020

Thermo-optic tuning of spectral broadening in a nonlinear Ultra-Silicon-Rich Nitride grating

Jae-Woo Choi

Temperature tuning of spectral broadening induced by a nonlinear grating is experimentally demonstrated. The bandwidth is observed to decrease as temperature increases, corresponding to a red-shift in the high dispersion region of the Bragg grating. ...

IEEE2020

Soft-phonon driven hexagonal-orthorhombic phase transition in BaVS3

Helmuth Berger

The lattice dynamics of low-dimensional BaVS3 is reported across the hexagonal-orthorhombic phase transition occurring at T-S = 250 K using a combination of the thermal diffuse scattering of x rays, inelastic x-ray scattering, and density functional theory ...

2019

Ultrafast Structural Dynamics along the beta - gamma Phase Transition Path in MnAs

Eugenio Ferrari

We investigate the orthorhombic distortion and the structural dynamics of epitaxial MnAs layers on GaAs(001) using static and time-resolved x-ray diffraction. Laser-induced intensity oscillations of Bragg reflections allow us to identify the optical phonon ...

AMER PHYSICAL SOC2019

Laue microdiffraction characterisation of as-cast and tensile deformed Al microwires

Andreas Mortensen, Helena Van Swygenhoven, Léa Deillon, Steven Van Petegem, Suzanne Godelieve Alphonsine Verheyden

Single-crystalline cast aluminium microwires with a diameter near 15 are characterised by Laue microdiffraction. A microwire in the as-cast condition exhibits a misorientation below over a length of 500 . The measured density of geometrically necessary dis ...

TAYLOR & FRANCIS LTD2019

Characterization of crystallographically etched single crystal diamond diffraction gratings

Olivier Martin, Niels Quack, Toralf Scharf, Marcell Kristof Kiss

We report on the fabrication and experimental characterization of single crystal diamond diffraction gratings fabricated with crystallographic dry etching. High aspect ratio atomic force microscopy reveals a characteristic V-groove profile exhibiting smoot ...

IEEE2018

Theta laser

Camille Sophie Brès, Svyatoslav Kharitonov

An unidirectional short-wave infrared fiber laser, comprising a theta cavity, with a gain unit based on rare-earth cations-doped fiber, the theta cavity having a ring cavity with two additional 2 input ports×2 output ports directional couplers DC1 and DC2 ...

2018

Laue micro-diffraction and crystal plasticity finite element simulations to reveal a vein structure in fatigued Cu

Helena Van Swygenhoven, Nicolò Grilli, Ainara Irastorza Landa

The formation of a vein during cyclic shearing of a single copper crystal oriented for single slip can be followed in transmission Laue diffraction by analyzing the spatially resolved lattice rotation evolution. Because Laue transmission integrates the sig ...

2017

Near-field characterization of Bloch surface waves based 2D optical components

Richa Dubey

Bloch surface waves (BSWs) are surface electromagnetic modes that propagate at the interface between a multilayer substrate and a homogeneous external medium. The optical field of the surface mode is confined near the surface of the multilayer. This vertic ...

EPFL2017

Structure of amorphous GeSe9 by neutron diffraction and first-principles molecular dynamics: Impact of trajectory sampling and size effects

Assil Bouzid, Carlo Massobrio

The structure of glassy GeSe9 was investigated by combining neutron diffraction with density-functional-theory-based first-principles molecular dynamics. In the simulations, three different models of N = 260 atoms were prepared by sampling three independen ...

Amer Inst Physics2016

In-situ Laue diffraction to follow dislocation patterning during fatigue

Ainara Irastorza Landa

The macroscopic strength of metals is determined by the dislocation arrangements that are formed when dislocations slip in the crystal lattice in response to the applied stress. Despite the extensive research carried out, the transition from uniform to non ...

EPFL2016