The incorporation of the doping element Na as well as the impact of this element on the structural, morphological and optical properties of evaporated CuInS2 films on Corning 7059 glass substrates is studied. The element Na was evaporated from a thermal evaporation source. The amount of the Na source was determined to be 0–1 at.% compared with CuInS2 source. The substrate temperature was maintained at 200 °C. The effects of Na on films properties were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical transmittance and reflectance spectra. SEM observation revealed the increase of the surface crystallinity and an enhancement of surface grain size with Na doping. The optical properties of the CuInS2:Na films revealed direct optical transitions which were attributed to the fundamental edge. The optical band gaps of the thin CuInS2:Na films decrease linearly with increasing the Na concentration. An unstable N type conductivity was firstly determined after what the layers are converted to P-type conductivity.

In this paper, we report the theoretical predictions of a high-index GaAs substrate ((111)A and (311)A) on the subband structure and thereafter on the 2D electron density of Si δ-doped Al0.33Ga0.67As/In0.15Ga0.85As/GaAs pseudomorphic high electron mobility transistor (pHEMT) with an additional InxGa1-xAs (x > 0.15) thin layer embedded in the channel. We have seen that the electronic structures and the electron density are quite sensitive to the additional InxGa1-xAs (x > 0.15) layer thickness, indium composition and to their position in the channel. An optimal position of the additional InxGa1-xAs layer was found to be corresponding to the maximum of the first eigen envelope function for the different growth directions. We report that the optimised electron density is obtained in the structure grown on (111)A GaAs substrate. In this case the electron transfer is significantly higher than those grown on (311)A and (001) GaAs substrates respectively.

This paper reports an attempt to improve the response of a metalloporphyrin Langmuir-Blodgett films, n-tetraphenyl porphine ruthenium (II) carbonyl, towards several vapor samples by means of surface microstructure modification. Four different surface microstructures were prepared by annealing the thin films samples in air at three different temperatures; 50, 100 and 150 $^{\circ}$C, for one hour. Three types of vapor samples with different physico-chemical properties, namely saturated vapor of methanol, ethanol and 2-propanol in 15 l/min of air flow, were used. The sensing sensitivity was based on the change in the optical absorption of the film upon exposure towards the gas samples that was measured at a particular wavelength, i.e., 514 nm, of the light source. It was observed that the response of the thin films was influenced by its surface microstructure, which the smoother the surface the higher the response is. The correlation between the microstructure of the films surface and its gas sensing property will be discussed.

This paper describe the recent measurements of `Electron efficiency' which has been done with the `CLIO' Free-electron laser (FEL). The `Electron efficiency' is the relative energy loss of the electron beam in the undulator during the FEL interaction. It gives an absolute measurement of the optical power produced by the FEL, which is then compared to the direct measurement using a power meter at the exit of the FEL. A analytical expression of the `Electron efficiency' is given here, and it is compared to the measurements.

Thin films of polytetrafluoroethylene (PTFE) were prepared by pulsed-laser deposition (PLD) from bulk PTFE targets using 157 nm F2-laser radiation. The films were analyzed by means of optical polarization microscopy, stylus profilometry, XPS, XRD, FTIR spectroscopy, and by capacitance measurements. The effect of substrate temperature, Ts, on the morphology and crystallinity of the films was studied. Films treated at sufficiently high Ts consist mainly of spherulite-like crystallites. Films with a thickness of more than about 155 nm are continuous, pinhole-free, well adherent to the substrate, and have a composition which is similar to that of the target material. The minimum film thicknesses and deposition rates are much lower than those achieved with pressed PTFE powder targets using 248 nm KrF-laser ablation. This is related to the different deposition mechanisms. Film formation based on KrF-laser ablation of pressed powder targets is mainly related to the condensation of large particulates transferred in a particle jet from the target to the substrate. F2–laser ablation and film formation seems to be based on the ablation and condensation of small fragments. Correspondingly, the morphology, crystallinity, and the optical and dielectrical properties of films significantly differ from each other.

The exchange charge model of the crystal field is applied to calculate the complete energy level scheme of the Cr4+ ions in Y3Al5O12 using $D_{2d}$  symmetry at the Cr4+ position. Mixture of the spin-triplet states arising from the  $^{3}F$ and $^{3}P$ terms of the 3d 2-electron configuration is shown to have a profound effect on the energy levels sequence. Large splittings of the orbital triplets originating from the “parent” Td symmetry are explained by large contribution of the low-symmetry component of the crystal field. Huang-Rhys parameter and effective phonon energy are evaluated from the experimental spectroscopic data available in the literature. Temperature-dependent probability of the nonradiative transition between the ground and first excited states is drawn; the emission band shape is obtained using the single configuration coordinate model.

The instability of an accelerated solid slab with elastoplastic properties is analysed by means of numerical simulations. The study is performed in the framework of experiments to be carried out at the future synchrotron facility SIS100 at the Gesellschaft fűr Schwerionenforschung (GSI), Darmstadt, which consider the implosion of a heavy pusher layer driven by the expansion of a material heated by an intense beam of heavy ions. We have found that for the megabar pressures involved in these experiments, the solid pusher may retain elastoplastic properties that are beneficial for the stabilization of the shortest perturbation wavelengths.

The predicted acceleration performance of the ram accelerator at elevated pressures, based on the quasi-steady model, is much greater than that observed in experiments. This discrepancy is attributed to the increase of mass of the propellant accumulating in the control volume, such that it approaches the mass of the projectile itself. A revision of the conservation equations to account for unsteady flow effects was conducted. The corresponding predicted thrust as a function of Mach number is significantly less than that derived from the quasi-steady model. By using a virial-type equation of state for the combustion products, a better agreement with experimental data was obtained using this unsteady modeling approach.

In this paper, we present a model of a hysteresis motor based on Maxwell's equations coupled with the Jiles-Atherton (J-A) hysteresis model solved by the finite element method. The aim of this work is to validate such a model by comparison with the experimental results (electromagnetic torque, voltage, current). We also present an analysis of this motor when imposing current or voltage in the 2D vector potential formulation.

The evaluation of the power brought by an electric arc to the surface of the electrodes still remains an important problem. In this paper we propose a method allowing a macroscopic approach of the power balance at the surface of a copper cathode submitted to a non stationary electric arc in argon. This method is based on a spectroscopic measurement of the instant of apparition of copper vapour in the arc and on the use of a numerical modelling of thermal phenomena occurring in the electrode. Under some simplifying assumptions, we reach an interval of possible values for the power and the surface density brought to the electrode by the arc.