The floating zone method is currently used to obtain Y123 melt textured bars, however the final sample length is always limited by the sample lower part weight which is sustained only by the liquid phase tension surface energy. Indeed, the basic scheme is to attach the bar only by the upper part and the lower part is totally free. A vertical furnace permits then to heat locally the bar and to create the floating zone. The sample translation at low speed (about 1 mm/h) allows the formation of a re-crystallization zone, according to the well known reaction Y211+Liquid (Ba and Cu rich) $\to$Y123, permitting the fabrication of a well textured bar. This work is devoted to present a modification of this process in order to have no limitation in the sample length. The idea which is developed here is to include inside the bar and co-axially a platinum wire. We have chosen a platinum wire due to its high melting temperature and its relatively low reactivity with Y123. We present here results obtained in term of reactivity, texture formation and superconducting properties when Y123 is textured in the presence of platinum wire versus different doped element introduced in the initial mixture.

The redistribution of Ni in InP is studied by annealing samples of InP implanted with 0.9 MeV Ni at 60o angle of ion incidence with respect to target surface normal as a function of dose (8.5×1012−4.5×1015 cm−2). Ni profiles are measured by secondary ion mass spectrometry (SIMS) and implantation induced damage by Rutherford backscattering spectrometry in channeling (RBS/C) condition. The highest dose sample is characterised by remarkable Ni accumulation near the surface (at ∼$0.3R_{\rm np}$) that has not been observed earlier along with two other distinct accumulation zones at Rnp+$\Delta R_{\rm np}$ and $2.2R_{\rm np}$ after annealing at 650 °C for 30 min. Here, Rnp is the normal component of the projected range for oblique angle bombardment.

N-type lightly doped germanium has been irradiated at room temperature with different particles: swift heavy ions, protons and electrons. Hall effect measurements have been carried out versus either the temperature (at a given fluence) or the fluence (at room temperature). Using the level positions determined by DLTS results previously reported, we extract from the Hall coefficient simulation at low doses the creation kinetics of the irradiation-induced defects. These defects are typically at room temperature the A-centre, the E-centre and the divacancy complexes. At higher doses, in the case of electron irradiation, these simulations are still feasible using only the previous defects mentioned above since the material leads towards a quasi-intrinsic state. But we point out that it is necessary in the case of proton and swift heavy ion irradiations to add an acceptor level in the forbidden band probably associated with a multivacancy defect. Indeed, in these cases, the material becomes p-type. Finally, the experimental introduction rates are compared to the theoretical ones. It appears that the relative damage creation efficiency is not very different from a projectile to another, proving that there is no strong dependence on the electronic energy loss.

Carbon nitride films synthesised by magnetron sputtering at different substrate temperatures have been studied using electron energy loss spectroscopy (EELS) during annealing performed in situ in a transmission electron microscope (TEM). The proportion of sp2 hybridised carbon slightly decreases initially during heating, presumably because of the removal of defects in the structure, whilst it increases at higher temperatures when graphitisation tends to take place, as confirmed by high resolution electron microscopy (HREM). Substantial amounts of nitrogen (up to ~ 80% ) are removed following annealing at 1000 °C. A corresponding decrease in the pre-peak of the nitrogen spectra suggests that pyridine-like N is released by annealing. As this peak component decreases, a second peak, of weaker intensity, is becoming apparent in the EELS spectra when the films are heated at temperatures above approximately 700 °C. The possibility has been suggested that this corresponds to N substituted for C in a graphitic structure, with possibly also some N2 contributing to the peak.

An original method enabling the in-situ and real time monitoring of a polymer structure evolution using an inserted piezoelectric sensor is presented. The validation of this technique is done at constant temperature by comparison to the results obtained on several polymers by classical ultrasonic methods in practically the same conditions. The complete validation is achieved by monitoring the complex cure of a polymer matrix fibre reinforced composite PMR-15 under sever conditions of temperature.

The magnetic material's deformation caused by magnetostriction is represented by an equivalent set of mechanical forces, giving the same deformation to the material as magnetostriction does. This is done in a way similar to how thermal stresses are usually incorporated into stress analysis. The resulting magnetostriction force distribution can be superposed onto other force distributions, like the magnetic force distribution. These two force distributions are the key ingredients of a numerically strong coupling of the magnetic and the mechanical finite element systems.

This paper presents two structures of superconducting coils able to give satisfactory solutions to the problem of generation of uniform field of high magnetic forces. The first structure is modeled by the use of purely surface current densities, whereas the second one can be described with volume current densities. Both of these structures proceed from the study of a particular expression of the complex magnetic potential introduced for structures with two-dimensional geometry. This work is carried out in a research collaboration between the GREEN and the DSM-DAPNIA department of the CEA Saclay.

The magnetic circuit of power transformers is built with magnetic oriented grain sheet. These modern sheets present a more and more narrow static hysteresis cycle, as well as an important remanent flux density, generally larger than 1 tesla. Although such a magnetic circuit necessarily includes joint air gaps, the experiment shows that these don't lead to an appreciable weakening of remanent fluxes. In order to explain the “paradox” of the existence of an important remanent fluxes in the magnetic circuits including air gaps, we propose a new model of joint called "pseudo-variable air gap" allowing to account for the nature of the type of joint: butt or overlap. It is shown that the new model fully explains the existence of an important remanent when the overlap joint has been used (which corresponds to the power transformer case), as well as the nearly total disappearance of the remanent fluxes in case of butt type joint. In addition, this model could be easily implemented in a global transformer model; which contributes to the improvement of the transformer models deriving from the circuit theory.

This paper presents a model taking into account moving bodies. An electrodynamic device which consists of a magnet over a superconductor shall be examined. In order to determine the mechanical behaviour of the device a coupled solution of the electromagnetic and the mechanical problem is used.

When performing the analysis of electromechanical transient problems with movement, it is needed to take into account the air gap deformation with time. A new remeshing procedure is proposed. It is based on node displacements coupled to a Delaunay algorithm. The node movement is described using bubbles in association with a physical model. The procedure generates high-quality meshes.

Optically pumped magnetometers are scalar magnetometers which are particularly suitable for mobile applications for which it is necessary to use an isotropic sensor. Our group has recently designed a new helium magnetometer with reduced sensor orientation effects. In this paper, we present the results about frequency spatial isotropy and show frequency effects smaller a 240 pT.

Continuum-mechanic derivations of the entrainment of rarefied gases induced by a surface acoustic wave (SAW) along the wall in a confined microtube are conducted by the perturbation method. Both no-slip and slip flow results are presented with the former ones matched with the previous approach by Yin and Fung. The critical reflux pressure-gradient values decrease as the Knudsen number increases from zero. Meanwhile, the (perturbed) mean flow induced by SAW along the wall of a microtube is proportional to the square of the wave-amplitude ratio which has been confirmed by previous experiments.