A5077981332- Glass properties and applications
- Photonic Crystals and Applications
- Advanced ceramic materials synthesis
- Advanced Surface Polishing Techniques
- Building materials and conservation
- Ferroelectric and Piezoelectric Materials
- Luminescence Properties of Advanced Materials
- Pigment Synthesis and Properties
- Recycling and utilization of industrial and municipal waste in materials production
- Nuclear materials and radiation effects
- Material Dynamics and Properties
- Rock Mechanics and Modeling
- Pickering emulsions and particle stabilization
- Multiferroics and related materials
- Cultural Heritage Materials Analysis
- Structural Analysis of Composite Materials
- Material Science and Thermodynamics
- Electronic and Structural Properties of Oxides
- High-pressure geophysics and materials
- Metallurgical Processes and Thermodynamics
- Surface Roughness and Optical Measurements
- Geological and Geochemical Analysis
- X-ray Diffraction in Crystallography
- Mesoporous Materials and Catalysis
- Adhesion, Friction, and Surface Interactions
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2016-2025
CEA Paris-Saclay
2016-2025
Centre National de la Recherche Scientifique
2016-2025
Université Paris-Saclay
2016-2025
Service de Physique de l'État Condensé
2014-2024
CEA Paris-Saclay - Etablissement de Saclay
2020-2022
Institut Rayonnement-Matière de Saclay
2010-2015
Direction des énergies
2014-2015
DSM (Netherlands)
2005-2006
University of Southern California
2006
▪ Abstract Atomistic aspects of dynamic fracture in a variety brittle crystalline, amorphous, nanophase, and nanocomposite materials are reviewed. Molecular dynamics (MD) simulations, ranging from million to 1.5 billion atoms, performed on massively parallel computers using highly efficient multiresolution algorithms. These simulations shed new light (a) branching, deflection, arrest cracks; (b) growth nanoscale pores ahead the crack how coalesce with cause fracture; (c) influence these...
Epitaxial oxynitride films have promising genuine electronic properties but are very challenging to engineer due a detrimental imbalance between nitriding and oxidation. The crystalline growth of BaTiO3 thin doped by atomic ion-nitrogen plasma-assisted molecular beam epitaxy has been studied on SrTiO3(001) substrates. Several conditions for nitrogen insertion in the perovskite lattice were considered. N-doped layers compared undoped produced with an oxygen plasma source only. Oxynitride...
Amorphous silica density at ambient pressure is known to depend on thermal history (through the quenching rate) but also, room temperature, maximum applied in past. Here we show that beyond density, a mechanical loading can endow structure with an orientational order. Molecular dynamics simulations evidence amorphous develops permanent anisotropic after extended shear plastic flow. This anisotropy which survives for unstressed specimen revealed markedly by fabric tensor computed over Si-O-Si...
The roughness of fracture surfaces exhibits self-affinity for a wide variety materials and loading conditions. universality the range scales over which this regime extends are still debated. topography these is however often investigated with finite contact probe. In case, we show that correlation function can only be measured down to length scale $\ensuremath{\Delta}{x}_{c}$ depends on probe size $R$, Hurst exponent $\ensuremath{\zeta}$ surface its topothesy $l$, spurious behavior at...
We measure the thickness of heavy water layer trapped under stress corrosion fracture surface silica using neutron reflectivity experiments. show that penetration depth is 65-85 Å, suggesting presence a damaged zone ∼100 Å extending ahead crack tip during its propagation. This estimate size compatible with other recent results.
Fractoluminescence experiments are performed on two kinds of silicate glasses. All the light spectra collected during dynamic fracture reveal a black-body radiator behaviour, which is interpreted as crack velocity-dependent temperature rise close to tip. Crack velocities estimated be order 1300 m/s and process zones shown extend over few nanometers.
This topical review is dedicated to understanding stress corrosion cracking in oxide glasses and specifically the (SBN) ternary glass systems. Many papers already exist on topic of complex or overly simplified (pure silica). These look at how systematically controlling environmental factors (pH, temperature...) alter cracking, while maintaining same type sample. questions still exist, including: What sets limit? velocity versus intensity factor slow regime (Region I)? Can researchers...
We present a study of adsorbate screening surface charge in microscopic ferroelectric domains sol–gel grown PbZr0.2Ti0.8O3 thin film. Low-energy and photoemission electron microscopies were employed to characterize the temperature dependence polarization written by atomic force microscopy. role charged adsorbates polarization-bound charges. demonstrate that full-field microscopy is suitable for determination system properties such as Curie temperature.
Abstract The understanding of domain structures, specifically walls, currently attracts a significant attention in the field (multi)-ferroic materials. In this article, we analyze contrast formation full electron microscopy applied to domains and walls uniaxial ferroelectric lithium niobate, which presents large 3.8 eV band gap for conductive have been reported. We show that transition from Mirror Electron Microscopy (MEM – electrons reflected) Low Energy (LEEM backscattered) gives rise...
We investigate initiation, growth, and healing of wing cracks in confined silica glass by molecular dynamics simulations. Under dynamic compression, frictional sliding precrack surfaces nucleates nanovoids which evolve into nanocrack columns at the tip. Nanocrack merge to form a crack, grows via coalescence with direction maximum compression. Lateral confinement arrests growth partially heals crack. Growth arrest crack occur repeatedly, as observed compression experiments on brittle solids...
A scientific hurdle in manufacturing solid films by drying colloidal layers is preventing them from fracturing. This paper examines how the rate of liquids influences particle packing at nanoscale correlation with crack patterns observed macroscale. Increasing results more ordered, denser structures, and dried samples have cracks. Yet, introducing a holding period (at prescribed point) during protocol disordered structure significantly less To interpret these observations, this conjectures...
We analyze the intermittent dynamics of cracks in heterogeneous brittle materials and roughness resulting fracture surfaces by investigating theoretically numerically crack propagation an elastic solid spatially-distributed toughness. The motion split up into discrete jumps, avalanches, displaying scale-free statistical features characterized universal exponents. Conversely, ranges scales are non-universal mean avalanche size duration depend on loading microstructure specimen parameters...
We report on the Fe doping and comparative Ni-Fe codoping with composition close to $\mathrm{NiF}{\mathrm{e}}_{2}$ of fully oxidized $\mathrm{BaTi}{\mathrm{O}}_{3}$ layers (\ensuremath{\sim}20 nm) elaborated by atomic oxygen plasma assisted molecular beam epitaxy; specifically any role vacancies can be excluded in our films. Additionally classical situ laboratory tools, films were thoroughly characterized synchrotron radiation x-ray diffraction absorption spectroscopy. For purely Fe-doped...
We report a study of α-[P2W18O62]6–, Wells–Dawson polyoxometalate (POM) layers deposited on indium tin oxide (ITO)-coated glass substrates. A variety techniques have been used including atomic force microscopy for surface topography characterization, current mapping, and current–voltage characteristics, X-ray photoemission spectroscopy chemical analysis, UV–visible determination band line-ups, energy dispersive reflectivity layer thicknesses scattering length densities. The conditions film...
Homogenization schemes based on continuum mechanics provide the elastic properties of dried colloidal layers (using no fitting parameter), yet inter-grain adhesion becomes relevant at higher porosities.
The process of colloidal drying gives way to particle self-assembly in numerous fields including photonics or biotechnology.