Large Angle Convergent Beam Electron Diffraction (LACBED) experiments on dislocations located in the mirror planes of icosahedral AlPdMn single grains show that – as previously inferred from standard image contrast technique – the direction of the Burgers vector is perpendicular to the mirror plane of movement, thus confirming the fact that climb should be an important process for the plasticity mechanisms in icosahedral quasicrystals.

We present experimental results on longitudinal magneto-optic Kerr effect in composite systems based on thin Fe layers associated with amorphous alumina (Al2O3). [Al2O3/Fe]m -samples ( $m=1,\,2$ ) have been prepared by rf magnetron sputtering onto Si(100) substrate. We have investigated the effect of the Al2O3 and Fe thicknesses on the Kerr rotation. The geometry of the multilayers is predicted theoretically by using deduced experimental magneto-optical constants. It will be shown how large Kerr rotation values can be obtained by adjusting sample parameters. For instance, a Kerr rotation close to 7° has been observed from an Al2O3/Fe/Al2O3/Fe/Si multilayer. The reflectivity and the figure of merit are discussed as a function of the Al2O3 thickness.

An analytical method is proposed to calculate the free surface deformationinduced by an inclusion embedded in a thin slab. The displacement of thefree surface has been determined with the help of the 2D Fourier transformation,as well as the momenta of the displacements when they exist. Comparing thedeformations induced by the same inclusion in a semi-infinite medium and ina slab, it has been demonstrated that the deformations in the slab are muchmore localized than in a semi-infinite solid. A simple example is finallygiven concerning a latent track induced by swift heavy ion going through asolid.

Bimetallic particles (10–20 nm), with a Cu or Ag core and a Pd shell were elaborated by sequential impregnations on various oxides. Their shapes are limited by (100) and (111) faces which correspond to the planes of lowest surface energy for pure fcc metal particles of the same size. The Pd shells are epitaxially oriented on the core and locally accommodated to the metal lattice. In the case of Pd/Cu particles, annealing at 400 °C induces the structural transition to the ordered structure with shapes limited by (111), (001) and (110) faces. The adhesion energy of the annealed particles does not seem to depend on the substrate.

The properties of Cr3+ in LiNbO3 single crystals have been investigated by means of several experiments including the recordings of absorption and high resolution laser spectroscopy spectra with dye-laser excitation spectra, emission spectra and fluorescence decays under laser selective pumping. Measurements performed on crystals with composition varying between congruent and close to stoichiometry enabled new features to be revealed which lead us to re-interpret the optical spectra of chromium-doped LN. Three chromium centres are sufficient to explain the main optical features. The main chromium centre labelled γ, giving rise to the broad absorption and emission bands, corresponds to the low-crystal field scheme where the 4T2 level is lower than 2E. The two other chromium centres α and β yield sharp lines in emission and correspond to the high-crystal field scheme. Their dependencies on both the chromium concentration and the composition were studied using emission spectroscopy at low temperature. The main centre γ seems slightly affected by chromium concentration or composition change. The centres α and β are shown to be strongly connected to the presence in their surrounding of intrinsic defects related to the crystal non-stoichiometry. From their behaviour versus Cr concentration, the origin of these centres is discussed in terms of perturbed substitution.

The scanning electron microscope mirror (SEMM) method is considered as a suitable approach for the characterisation of the charge trapping ability of insulators. However, the interpretation of the experimental results is far from being obvious. The aim of this paper is to give some new insights in this problem. Our description of the mirror plots is conventionally based on a multipole analysis of the charge distribution and on the radius of curvature approximation. This approach indicates that the trend of the plots is mainly controlled by the quadrupole contribution. This clearly illustrates the non-uniqueness of the interpretation since different trapped charge distributions, but with nearly equal quadrupole terms, can produce rather similar mirror plots. To make the problem unambiguous, a semi-ellipsoidal shell model is used to account for the implanted space charge. Within this model, we propose a simple method to get the mean density of trapped charge ρ 0. Our Monte Carlo simulations of the charge implantation phase show that ρ 0 can strongly differ from the density of traps N T. The reasons for these deviationsare discussed for a significant set of values of N T and of the primary energyE p.

The presented study concerns the dynamics of the arc in alow-voltage breaking device. For this study, two methods ofdiagnostics are used: a magnetic diagnostics based on punctualmeasurements of the induction and an optical diagnostics using ahigh-speed camera and a CCD camera. These two diagnostics arecompared for different experimental conditions.

The 3 GHz linac section designed for the low energy (7–65 MeV) part of TOP (Therapy Oncological Protons) linac consists of eight modules of the structure SCDTL (Side Coupled Drift Tube Linac). The non axisymmetric cavities required a full 3D modelling. Electromagnetic calculations carried out by using MAFIA code gave the full mode spectrum, power losses, the coupling coefficients distribution and some indications for the tuning procedure. This paper reports a comparison between the results of this study and some RF measurements on the first module (7–13.4 MeV).

A new approach is developed to estimate the geometrical factors, solid angle approximation and geometrical efficiency for a system with experimental arrangements using X-ray tube and secondary target as an excitation source in order to produce the nearly monoenergetic Kα radiation to excite the sample. The variation of the solid angle is studied by changing the radius and length of the collimators towards and away from the source and sample. From these values the variation of the total solid angle and geometrical efficiency is deduced and the optimum value is used for the experimental work.