Publications de Pierre Stadelmann

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Evidence of composition fluctuations around threading dislocations at scales ranging from atomic distances to tens of nanometers is provided by z-contrast imaging, strain measurement, and energy dispersive x-ray spectroscopy in AlxIn1-x N/GaN heterostructu ...

We have used accurate convergent beam electron diffraction to determine the structure factors of the reflections most sensitive to the valence-electron distribution in Mg2Si. The experimental values agree well with calculations of the structure factors bas ...

We have developed a straightforward synthetic route to prepare core-shell systems based on gold nanoparticles (NPs) surrounded with J-aggregates molecules. This synthesis allows the direct and efficient coating, at room temperature, of pretreated citrate-s ...

Electron energy loss spectroscopy in a high-resolution transmission electron microscope has recently been used with success to characterize the electronic properties of closed cage nanometer-size graphitic particles. In the plasmon region, the experimental data reveal interesting size-dependent variations, which are not yet fully understood. The difficulties encountered in the interpretation of the spectra are principally due to the lack of a complete theoretical treatment of the anisotropic dielectric resp

In the absence of high-order aberrations, the lattice fringe technique should allow measurement of grain boundary rigid-body displacements to accuracies about an order of magnitude better than the point-to-point resolution of the transmission electron microscope. The three-fold astigmatism, however, introduces shifts of the lattice fringe pattern that depend on the orientation of the lattice relative to the direction of the three-fold astigmatism and thus produces an apparent shift between the two grains bo

A method for preparing and observing clay platelets for size and shape analysis using scanning electron microscopy (SEM) was developed. Samples of the clay platelets were prepared by polyelectrolyte-assisted adsorption onto a pyrolytic graphite surface. The use of graphite as a substrate was advantageous because of the low number of secondary electrons emitted from it during imaging by SEM. The resulting low background noise allowed the emission from the 1 nm thick clay sheets to be clearly visualized. Ima

With the idea of operating the factors affecting the mobility or the pinning of ferroelectric domain walls in AB03 perovskites, high resolution electron microscopy has been performed to provide a better knowledge of the walls themselves in PbTiO/sub 3/. The transition between two domains with their polarisation vectors at right angles appears to be along the (101) twin planes. The Maxwell equations can be satisfied by a highly localized space charge rather than a lattice distortion. As the heavy atom Pb lat

High mobility Al0.28Ga0.72N/GaN two-dimensional electron gas (2DEG) is achieved on ( 111) oriented single crystal diamond substrate. The surface morphology of the epilayer is free of cracks thanks to the use of an AlN interlayer for strain relaxation. The ...

We report a simple chemical-route to BN multiwall nanotubes decorated with nanosheets. These nanostructures have been prepared on a large scale from a simple unique chemical process under an ammonia flow onto the surface of an alumina substrate, using carb ...

High-aspect-ratio, monocryst. Cd chloride nanowires doped with fluorescent CdS nanoparticles were synthesized using planar lipid membranes as templates. Cd2+ ions bound to the lipid bilayers (a) are released at low pH to the nanometer-sized, interlamellar ...

The integrated intensity of the diffracted beams present on microdiffraction precession patterns can be used to infer the 'ideal' symmetry, i.e. the symmetry which takes into account both the position and the intensity of the diffracted beams on a diffract ...

High-resolution transmission electron microscopy (HRTEM) and HRTEM simulation by the Bloch wave method (JEMS) are used to determine the structure and thickness of micro- and nanocrystals of biominerals and hydroxyapatite grown from aqueous solutions. It is established that thin (from one to several lattice parameters) crystals, including hydroxyapatite in mineralized biological tissues, are usually formed in low-temperature (up to 40degreesC) solutions. Relatively thick (up to several tens of lattice parame

We investigated the interdiffusion of InGaAs/InP quantum wells (QWs) due to rapid thermal annealing (RTA) by photoluminescence (PL) spectroscopy and wedge transmission electron microscopy (WTEM). After RTA at temperatures between 650 and 900 degrees C (annealing time 1 min) we observed large emission energy shifts of up to 210 meV. From the temperature dependence of the PL emission energy shifts, the interdiffusion lengths, interdiffusion coefficients and activation energies (e.g. of 2 eV) were determined u

An AlInN/AlGaN microcavity (MC) containing a GaN/Al0.2Ga0.8N multiple quantum well (MQW) structure is investigated through room temperature (RT) photoluminescence and reflectivity experiments. A vacuum Rabi splitting as large as 50 meV at RT is reported fo ...

Non-polar a-GaN films grown on r-sapphire by hydride vapor phase epitaxy (HVPE) are studied using transmission electron microscopy (TEM). Despite the small lattice mismatch in a-GaN ([1 0 (1) over bar 0] similar to 1.1% and [0 00 1] similar to 16%), high d ...

A novel approach based on the Stober method allows breaking of the symmetry of core-shell systems based on metallic core and metal oxide shell. By adjusting the proportion of the TiO2 precursor with regard to the silica precursor, different morphologies of ...

The core–shell structure of a range of acrylic–acrylic latexes has been investigated by combining different specimen preparation methods with transmission electron microscopy (TEM), dark-field scanning transmission electron microscopy (DSTEM) and low-volta ...

High-Resolution Electron Microscopy observations of gold particles are compared with images calculated using the multislice method for both regular f.c.c.-cuboctahedron- and Multiply-Twinned Particles -icosahedron, decahedron-. Although simulated for idea

Recent investigations of the tensile fracture behaviour of representative glassy and semicrystalline impact-resistant polymers are reviewed, with emphasis on the microdeformation behaviour as revealed by electron microscopy of sections from bulk specimens, where the crack-tip damage zone has been embedded and/or stained under load, and on thin films deformed in situ. The insight that such techniques have provided into the toughening mechanisms is discussed.

Pierre Stadelmann

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Stress-modulated composition in the vicinity of dislocations in nearly lattice matched AlxIn1-x N/GaN heterostructures: A possible explanation of defect insensitivity

Electronic structure of Mg2Si by combining electron diffraction and first-principles calculations

Core-shell gold J-aggregate nanoparticles for highly efficient strong coupling applications

Plasmon excitations in graphitic carbon spheres

The effect of three-fold astigmatism on measurements of grain boundary volume expansion by high-resolution transmission electron microscopy

Practical method for high-resolution imaging of polymers by low-voltage scanning electron microsopy

Study of ferroelectric domain walls in PbTiO/sub 3/ by high resolution microscopy and image simulation on a Cray-1S

High-Mobility AlGaN/GaN Two-Dimensional Electron Gas Heterostructure Grown on (111) Single Crystal Diamond Substrate

Boron nitride multiwall nanotubes decorated with BN nanosheets

Synthesis of nanoscopic optical fibers using lipid membranes as templates

The symmetry of precession electron diffraction patterns

HRTEM simulation in determination of thickness and grain misorientation for hydroxyapatite crystals

Investigation of InGaAs/InP Interdiffusion by Simultaneous Transmission Electron-Microscopy and Photoluminescence Analysis

Large vacuum Rabi splitting in a multiple quantum well GaN-based microcavity in the strong-coupling regime

Defects in a-GaN grown on r-sapphire by hydride vapor phase epitaxy

Core-shell Au@(TiO2, SiO2) nanoparticles with tunable morphology

The morphology of submicronsized core–shell latex particles: An electron microscopy study

The structure determination of small gold particles by high-resolution electron microscopy (HREM): image simulation and observations

Microdeformation in heterogeneous polymers revealed by electron microscopy

Temperature dependence of the structure and energy of domain walls in a first-order ferroelectric