Using the perturbation method (Born approximation), a theoretical model hasbeen developed to account for the EBIC intensities and contrasts likely to occur in ann-type polycrystalline semiconductor, as a function of the grain size. The influenceof the minority charge carrier diffusion length and the primary electron beam energyhave also been examined, respectively.

A united theoretical description of dielectric properties of molecular solids and liquids is developed. The numbering data are tabulated and some results are pictured. The theory expands the fundamental dispersion expressions of complexdielectric permeability, initiated by Debye for molecular liquids, to any condensedmolecular medium.

Thermally-induced grain boundary grooving has typically been characterized experimentally by either (1) optical interferometry (OI) or (2) reference line (RL) technique. For the OI technique, groove angle and groove width are reported and for the RL technique, groove angle, width and depth are reported. Even recent Atomic Force Microscope (AFM) studies of grain boundary grooving report their results in terms of groove angle, width, and depth exclusively. These measurements have been interpreted in terms of Mullins' 1957 theory on grain boundary grooving, which includes a derivation of the grain boundary groove profile. However, analyzing the groove depth, width, and angle uses only a small fraction of the groove profile information provided by Mullins' theory. In contrast to the literature, this study uses AFM data from thermal grooving in polycrystalline alumina to make a detailed comparison between Mullins' equation (and a modified form of Mullins' equation) for the entire groove profile rather than just the groove width or groove angle, thus providing a more rigorous and comprehensive test of theory. In addition, despite the wider and deeper grooves produced by microwave annealing, the modified form of Mullins' equation fits well both the microwave and conventionally annealed groove profiles.

Be diffusion during post-growth annealing has been investigated in InGaAs epitaxiallayers. Kick-out mechanisms considering species charges, built-in electric field andFermi-level effect have been studied. Several forms of kick-out mechanism have beenimplemented in our simulation programs. Experimental concentration profiles obtainedby SIMS analysis have been compared systematically with the numerical results ofsimulations. We have deduced that the kick-out mechanism Bei 0 ↔ Bes − + IIII + is the dominating diffusion mechanism in InGaAsunder our experimental conditions (C 0 = 3 × 19 cm−3). With our experimentaldata, we have found that the effective diffusion coefficient values areD = (7.7−9) × 10−13 cm2 s−1 at T = 700 °C and D = (1.4−1.5) × 10−11 cm2 s−1 at T = 800 °C which is severalorders of magnitude higher than most published data. A possible explanation would bethe effect of V/III flux ratio.

Effects of annealing and film thickness on the electrical and optical properties of Sb:SnO2films deposited by electron beam from bulk samples prepared using sintering technique have beeninvestigated. A compromise between low resistivity and high transparency of the film has been studiedusing the factor of merit. This factor, which has been found maximum for film 100 nm thick annealed at 550 °C for 15 min, seemed to be enhanced with increasing annealing time and/or film thicknessconfirming the simultaneous improvements of transparency and conductance with the latters. Other opticaland electrical parameters such as refractive index, width of energy gap, density of localized states,concentration and mobility of carriers and Seebeck coefficient have been studied also, discussed andcorrelated to the microstructure changes with annealing and film thickness.

PbZr0.52Ti0.48O3 (PZT) and YBa2Cu3O7−δ (YBCO) thin filmswere fabricated by a pulsed laser deposition (PLD) method. The Pt/PZT/Pt ferroelectric capacitors were fabricated on silicon substrates while the Au/PZT/YBCO capacitors were fabricated on LaAlO3 substrates. The capacitance-voltage (C-V) propertiesand the hysteresis loops of the capacitors were measured before and after γ-rayirradiation. The results show that for Pt/PZT/Pt capacitors, the remanent polarizationP r and the absolute coercive field E C increase while the dielectricconstant ε decrease with increasing accumulated dose. For the Au/PZT/YBCOcapacitors, P r and ε decreased with accumulated dose, but theabsolute value of the negative and positive coercive fields increased. The resultshave been interpreted by radiation-induced positive charge trapping at defects in theferroelectric materials.

This study reports on Be diffusion in InGaAsP layers grown by gas source molecularbeam epitaxy. The experimental structures consisted of a 2000 Å Be-doped(3 × 109 cm−3) In0.73Ga0.27As0.58P0.42 layersandwiched between two 5000 Å undopedIn0.73Ga0.27As0.58P0.42 layers. The samples were subjected to rapidthermal annealing in the temperature range from 700 to 900 °C with timedurations of 10 to 240 s. Secondary ion mass spectrometry was employed for aquantitative determination of the Be depth profiles. Concentration profiles of Be inInGaAsP have been simulated according to two kick-out models: the first modelinvolving neutral Be interstitials and singly positively charged Ga, Inself-interstitials, and the second model involving singly positively charged Beinterstitials and doubly positively charged Ga, In self-interstitials. Comparison withexperimental data shows that the first kick-out model gives a better description.

The X-ray diffracted intensity changes considerably when a static electric field is applied perpendicularly to a X- or Y-cut LiNbO3 platelet-shaped crystal. Section diffraction images (topographs) recorded using synchrotron radiation in transmission mode reveal the curvature of the lattice planes under such a field. A theoretical analysis based on the equations of electro-mechanical field in a piezoelectric medium together with chemical etching experiments allows us to explain this effect. Tiny inverted ferroelectric doMayns produced by the applied field exert a strain on the non-inverted bulk leading to the observed curvature of the lattice planes. This approach seems to be valid for other piezoelectric crystals of various symmetry classes.

Structural and vibrational properties are investigated in SiC nanopowders synthesized by a CO2 laser pyrolysis of (SiH4, C2H2) gaseous mixture and thermally treated up to 1800 °C. The structural modifications of the SiC crystallites and the arrangement of the carbon in excess are monitored at different annealing stages. A critical behaviour is revealed in the powder annealed at T a = 1500 °C through the features of the Raman spectra and the insulating-conductor transition. The significant electric conductivity (σ ≈ 0.05 S cm−1) which appears above T a is discussed with respect to the powder composition and the interface effects where the carbon in excess seems to play a key role.

Oxidation study, at 700 °C and under controlled atmosphere (oxygen partial pressure: 0.04 Pa) for 24 h, of unimplanted or yttrium implanted pure iron specimens was carried out using in situ X-ray diffraction to observe the yttrium implantation effect. In situ X-ray diffraction analyses performed on unimplanted pure iron clearly show the formation of FeO (wustite) and Fe3O4 (magnetite) compounds at the beginning of the oxidation test whereas the formation of Fe2O3 (hematite) is only detected after 1h30 of oxidation. In situ X-ray diffraction analyses performed with the same experimental conditions on yttrium implanted pure iron show the presence of two Mayn yttrium-iron mixed oxides (i.e. FeYO3 and Fe2YO4) in combination with wustite, magnetite and hematite structures. The presence of the Fe2YO4 compound is important because several authors have reported its anticorrosion properties at high temperature. X-ray diffraction results also show that the formation of FeYO3 and Fe2YO4 is Maynly reinforced at the gas-oxide interface which suggests an outward yttrium diffusion through the oxide layer from implanted pure iron.

The thermodynamic theory developed in [1] is extended to describe the uniaxialstress induced cubic-tetragonal martensitic transformation. The theory is found toprovide a good quantitative agreement with the experimentally observed σ − T phase diagram of martensitic transformation exhibited by Ni–Mn–Ga alloys (σis the uniaxial compressive stress in [110] direction).

During nanoindentation of MgO, a pop-in phenomenon has been observed, that is, an abrupt increase in penetration depth at a critical load. Atomic force microscopy investigations have been performed to characterise the dislocation structure in the vicinity of the indented area. The pop-in has been found to be the first stage of plastic deformation during nanoindentation. This phenomenon is ascribed to the nucleation and further propagation of interstitial loops of dislocations beneath the indenter. A three-dimensional model for a flat ended indenter is developed.

The use of a self-processing dry photopolymer layer capable of memorizing optical information as a local change in thickness, is proposed for the fabrication ofmicrolenses, binary holograms and gratings. Relief micro-optical elements aregenerated by direct imagewise exposure through a mask. A gradient of chemicalcomposition and a gradient of surface free energy cause the transfer of reactivespecies between dark and illuminated areas. Contrary to conventional lithographictechniques that require wet chemical post-treatment to remove parts of the photoresistmaterial, the fully self-processing character of this technique makes the recordavailable in situ and immediately after exposure.

Dielectricthin-film helicoidal bianisotropic mediums (TFHBMs)are rotationally nonhomogeneous nano-engineered materialsof recent vintage. Here,optical signatures of axially excited TFHBM slabsare calculated after solving a boundary value problem,after assuming the chosenmaterials to have single-resonance Lorentzian dielectric response properties.The spectrum of co- and cross-polarized reflectancesand transmittances, true and apparent circular dichroisms, trueand apparent linear dichroisms, ellipticity transformation,and optical rotation are presented. The role of the structural period in thespectral location of the circular Bragg phenomenon isdelineated, and measures to deepen thatphenomenon are discussed. The effects ofstructural handedness on the spectrum are also identified.

The aim of this paper is to present the NH2 dielectric behaviour in theprimary amines for the importance it bears in the interaction of aminoacids andproteins and their influence in the electric conduction processes. For that, thedielectric properties of 1-propylamine, 1-butylamine and 1-pentylamine have beenstudied. Measurements were performed between room temperature and −180 °C inthe low frequency range and micro-waves measurements were done between −40 °Cand 25 °C. The isofrequency recordings of dispersion ε′ and absorption ε′′, for these three primary amines, showclearly the relaxations and the effect of the aliphatic chain length.

Measurements of the complex, frequency dependent susceptibility, χ(ω) = χ′ (ω) − i χ′′ (ω) over the frequency range 50 MHz to 15 GHz, of a surfacted ferrofluid comprising MnFe204 ferrite particles in dibutylphthalat (DBP), as a function of a biasing magnetic field arepresented. The biasing field was varied over the range 0 to 100 kAm−1, and has enabledaverage values of anisotropy constant, $\bar{K}$ , and anisotropy field $\bar{H}_{\rm A}$ forthe sample to be determined. Ferromagnetic resonance was exhibited for all values of the biasing field, covering the range 1.2 to 8.5 GHz, with the χ′ (ω) component of the susceptibility going negative in the GHz region.

An optimised process is presented to fabricate co-planar metal-insulator-metal nanojunctions down to an inter-electrode distance of 5 nm. Simulation of the e-beam insulation of the PMMA/SiO2/Si interface is used to optimise the PMMA resist thickness and the exposure strategy. The process was well stabilised to provide a full statistical analysis of the number of nanojunctions produced per wafer. A 10% throughput was reached for 5 nm giving a mass production of about 100 nanojunctions per 2 inches wafer all equipped with their interconnection pads.

Sn-doped indium oxide (ITO) films have been investigated for fast rise time laser pulse detection for the first time. The detector was tested for different wavelengths in the UV (280 nm, resulting in inter-band transitions of electrons) and NIR (1.06 μm, resulting in free carrier absorption) region. Characteristics of laser induced voltages for the ITO films with different compositions have been studied for both excitation wavelengths. The voltage pulse generated by NIR-excitation was delayed in time at least by 100 ns as compared with that generated by UV-excitation. Responsivity of the films is larger for the UV-excitation than for the NIR-excitation.

This article investigates the electronic transport properties of ZnO/ CdS/ Cu(In,Ga)Se2heterojunction solar cells during and after illumination or forward bias in the dark.We observe a relaxation of the open circuit voltage under constant illumination as wellas a relaxationof the voltage drop over the device under constant forward biascurrent in the dark. Both phenomena are accompanied by an increase of the samplecapacitance. We introduce a general quantitative model concept for the open circuitvoltage relaxation and related effects in heterojunction devices that explains thephenomena as a consequence of the persistent capture of charge carriers within thespace charge region. We apply our concept to develop a specific quantitative model forthe observed metastablity in Cu(In,Ga)Se2 heterojunction solar cells.

A numerical study is made of the bandwidth to thickness ratio of radar absorbers for the suppression of normally incident waves. The study deals with single- and multi-layer dielectric absorbers, in which the frequency dispersion of the permittivity is allowed for. Analysis of the results permits obtaining a simple empirical relationship between thickness, bandwidth, and reflectance level of some specific kinds of absorbers. Essential features of different designs of dielectric radar absorbers are revealed and discussed.