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.

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.

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.

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.

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.

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.

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.

The effect of sequential deposition of Cu onto a 300 Å-thick film of layered InSe epitaxially grown onto a Si(111) substrate, has been studied by Auger electron spectroscopy (AES), low energy electron diffraction (LEED) and photoemission yield spectroscopy (PYS). Cu coverages were from a few hundredth of a monolayer (in terms of InSe atomic surface plane: 1 ML = 7.2 × 1014 at/cm2, that is 0.85 Å of Cu-metal) to 300 ML. The effect of annealings up to 370 °C was also studied. It is shown that Cu has first a non uniform bulk interaction with InSe which looks like an insertion which saturates at 1 ML of Cu per In2Se2 single layer. Then it forms islands which fully mask the surface beyond about 150 ML coverage (130 Å of Cu-metal). Upon annealings beyond 300 °C, the Si substrate behaves as a Cu sink.

Microwave absorption of sintered M-type hexaferrites (BaFe12−2x Rux Znx O19) is investigated as a function of the substitution ratio x. The substitution with Ru and Zn has been shown to reduce the axial anisotropy of the BaM-hexaferrite which becomes in-plane for x ≈ 0.4. Large saturation magnetization and in-plane magnetic anisotropy allow to obtain high permeability values at microwave frequencies. To study the behavior of the ferrites at these frequencies, the complex constitutive parameters ε and μ (respectively permittivity and permeability) are simultaneously measured from 0.5 up to 18 GHz using a coaxial technique. Two absorption phenomena are observed: the ferrimagnetic resonance and the domain wall relaxation; the latter is studied with the Globus' model. Anti-radar applications are also mentioned.

In the present paper, the equivalence between the magnetic images method and the classical variable separation method is set up. These methods are separately applied to calculate the magnetic scalar potentials and the magnetic vector potentials in the air-gap of some cylindrical synchronous machines, excited by surface permanent magnets with radial and/or azimuthal magnetisation, and without polar pieces. The rotor and the stator are assumed slotless, and the whole electric machine non saturated. The expressions of the magnetic scalar potentials of each method are interpreted, and their equivalence is established. The Mayn purpose of this paper is then the demonstration that the magnetic images method is applicable for the study of simplified synchronous machines. The interest of the magnetic images use in comparison with the variable separation method is shown.

In this paper, we analyse the ionizing irradiation influence on the characteristic current-voltage (V < 0 and V > 0) of the metal/ultra-thin oxide/semiconductor structures where the oxide thickness varies from 40 to 125 Å. The results obtained show that this influence is significant on the current corresponding to the carrier injection by the semiconductor (V > 0). When the thickness of oxide is higher than 100 Å, the radiation creates a positive charge in the oxide and decreases the conduction parameters (K 1 and K 2). For oxide thicknesses lower than 100 Å, the radiation does not create any charge in the oxide but improves the conduction parameters. This is attributed to the beneficial effect of the radiation on the defects characterizing an ultra-thin oxide layer.

The Mayn objective of this work is to analyse the influence of non-associativity and non-coaxiality (irregularity of yield or potential surfaces) on the strain localization modes in the framework of Rice's theory of bifurcation. The theoretical aspects of strain localization are recalled. Two kinds of material are studied: an overconsolidated clay and a sandstone. In the case of overconsolidated clay which is contractant, non-associativity of the plastic law is found to be sufficient for the capturing of localisation in the hardening regime. However, for a strong dilatant material such as Fontainebleau sandstone, non-associativity is no longer sufficient. Non-coaxial flow theory needs to be incorporated in the constitutive law to describe the bifurcation. Comparisons between numerical predictions and experimental data are provided.

This paper describes a multiwavelength optical pyrometer designed to measure, with a 3 ns rise-time, the evolution of a fast varying temperature as can be encountered in the detonation products of an explosive. By measuring six luminance temperatures within the visible and near infra-red spectra, this apparatus allows to determine a true surface temperature over the range 1500 to 6000 K. It has been used for studies of detonation in nitromethane, a transparent liquid explosive.