Xenon and krypton have been implanted into muscovite mica at room temperature and at liquid nitrogen temperature. The behavior of the implanted Xe and Kr was followed by low-temperature transmission electron microscopy and energy dispersive x-ray analysis. An electron diffraction pattern of diffuse bands is observed at room temperature due to the presence of fluid rare gas and to noncrystalline mica. Visible cavities with diameters 10–300 nm formed in the Xe-implanted mica. Visible cavities in room-temperature Kr-implanted mica ranged from 5–50 nm in diameter. The gas pressures at room temperature in the cavities are estimated, assuming all of the implanted gas precipitated in cavities to be ∼10 MPa for Xe and ∼20 MPa for Kr. These pressures are considerably lower than found for rare gases implanted in metals and ceramics, but sufficient to liquefy the rare gases at room temperature. The Xe and Kr were observed by dark-field microscopy to form fcc crystalline solids within the cavities at temperatures below their triple points, with lattice parameters of a (xe) = 0.630 ± 0.0015 nm and a (Kr) = 0.565 ± 0.005 nm. The solid Xe within bubbles was unstable under the electron beam of the transmission electron microscope at temperatures above 80 K, while the solid Kr within bubbles was unstable at temperatures as low as 35 K. The crystalline mica matrix undergoes a transformation from a crystalline structure to an amorphous structure as a result of implantation.

The microstructure of a muscovite mica exposed to a rare gas ion beam has been studied by transmission electron microscopy. The investigation of damage without implantation was carried out using argon and helium ions of sufficient energy to traverse the 100–150 nm mica specimens. For 340 keV Ar++ irradiation, amorphization of mica occurred at a fluence as low as 3.5 × 1014 ions · cm−2, which corresponds to 0.29 dpa. Muscovite can be amorphized using 80 keV helium ions, but this requires a much higher fluence and damage production of 4.6 × 10−6 ions · cm−2 and 0.60 dpa, respectively. Since helium irradiation results principally in ionization energy loss, it indicates that amorphization of muscovite results mainly from nuclear interactions. Complete amorphization of muscovite mica is found to take place for all ions at approximately the same amount of nuclear energy transfer to energetic primary knock-on atoms, assuming a recoil energy greater than 500 eV. This suggests that amorphization occurs directly in dense displacement cascades. A significant amount of helium, 100 ppm, can be implanted into muscovite mica without destroying the crystal structure.

Iron thin films on ion-etched monocrystalline AlGaAs(001) substrates were prepared using ion-beam sputtering deposition. The interface reaction was characterised by planar and cross-sectional transmission electron microscopy after annealing in vacuum at 400°C for 1h. Interdiffusion mainly results in the generation of Fe2As grains growing into the substrate, perpendicular to the Fe/AlGaAs interface. The iron-arsenide grains exhibit an either triangular or trapezoidal shape. Analyses on their morphology and size, as well as on the orientation relationships between Fe2As and AlGaAs phases were also carried out. The appearance of the Fe2As phase is discussed in terms of standard enthalpy for alloy formation. Finally a pyramidal growth model is proposed for Fe2As grains, which mainly involves the four close-packed {111}AlGaAs planes.

The kinetics of island nucleation, coalescence and growth during deposition of Au atoms on amorphous carbon are studied experimentally and the obtained results are analysed using rate equations. Rutherford backscattering spectroscopy (RBS), transmission electron microscopy (TEM), grazing-incidence small angle scattering (GISAXS) and atomic force microscopy (AFM) techniques are used to measure the quantity of deposited Au, density, size and average height of the islands as a function of time. Parameters used in rate equations are deduced from a quantitative comparison between calculated and experimental evolution of the above dependencies. Suggested rate equations take into account the adsorption rate on a bare substrate as well as on existing islands, the mobility of adatoms, possible redistribution of atoms between islands and bare substrate and coalescence of islands. The rate equations are used to study the kinetics of the coverage of a carbon substrate by gold atoms and the kinetics of the island density. It is shown that experimental and calculated dependencies are in agreement if the mobility of islands is included.

The paper deals with the interpretation of the results obtained from the depth profile measurements based on sputter analytical techniques for samples that were previously subjected by ion bombardment. It is shown that the changes in the kinetics of surface composition observed at the initial stages of depth profiling may not correspond to the real composition distribution for the near-surface region, but may be initiated by unbalanced fluxes between the sputtered atoms from the surface and mass transport in the near-surface layer taking place under concentration gradients formed by preferential sputtering. The influence of temperature that affects the process of segregation is considered and a possible segregation mechanism based on radiation induced phonons is investigated.

The redistribution of elements at and near the surface of alloys subjected to ion bombardment is reported. The kinetics of surface composition and the distribution profiles of elements in the subsurface layer are analysed during the transition time between two steady-state regimes of sputtering after changes in the irradiation conditions. Good agreement between the experimental and calculated results is obtained. It is shown that the surface composition variations observed after perturbation of ion beam parameters which lead to changes in the sputtering rate and interdiffusion coefficient are related to the redistribution of elements in the altered layer. The kinetics of surface composition during the transient time depend on the surface pre-treatment history.

Huang diffuse scattering was used to study the annealing behaviour of vacancies and interstitials produced by different types of hydrogen implantation. The results show the presence of point defect clusters with an anisotropic strain field.

We have implanted Hg0.3Cd0.7Te compounds with various ions (aluminium, xenon and krypton) at different substrate temperatures (300 and 15 K). Implantations were performed with impinging ions having a kinetic energy in the range 60–320 keV, their fluence varying between 5 × 1011 and 5 × 1014 ionscm−2. Samples have been characterized before and after annealing (300° C, 2 h) by SIMS, EBIC, TEM, RBS and differential Hall effect. The overall result is that the p/n transformation is linked to defects induced during implantation. The saturation in the sheet carrier concentration nsfor φ > 5 × 1013 Alcm−2 could be caused by fact that the recombination volume has then been reached.

p-type crystals of the ternary compounds Hg1−xCdxTe have been irradiated with high-energy ions and electrons. Electron-beam-induced current signals on xenon- and krypton-irradiated Hg1−xCdxTe show that n-type conversion, occurring all along the ion path, is related to the presence of mercury atoms. Resistivity and Hall measurements on carbon-, oxygen-, xenon- and electron-irradiated Hg0.8Cd0.2Te crystals allow us to determine the effective cross section for atomic displacement. We observe, for electron-irradiated samples, a saturation in carrier concentration interpreted as the pinning of the Fermi level at a resonant donor state 370 meV above the bottom of the conduction band. Comparison between ion and electron irradiations shows that electrically active produced defects are mainly due to atomic collisions. Additional reduction of defect production efficiency for xenon ions may be the onset of some energy transfer from electronic loss to target atoms.

Cd x Hg1−xTe (0⩽x⩽1) single crystals were strained by microhardness and by constant strain rate uniaxial compression tests, in the temperature range 300 to 600 K. Hardness curves as function of temperature can be described by empirical relations. Stress-strain curves, relaxation tests and dislocation observations using transmission electron microscopy show that the deformation is controlled by a thermally activated Peierls mechanism. Moreover, dislocations are dissociated with a stacking fault energy which does not depend on thex composition.

We irradiated Cd0.2Hg0.8Te samples at room temperature in the plastic range, with a CO2 laser beam the wavelength of which (λ=10 500 nm) is 20% longer than the absorption threshold. We observed a positive photoplastic effect (PPE) of the order ΔσPPE/σ≈4 to 5%.

This paper presents some aspects of the crystallization by ArF excimer laser pulses (λ = 193 nm, τ = 20 ns) of various energy densities (in the range 90–400 mJ cm-2) of a-Si: H films deposited by chemical vapour deposition on amorphous SiO2 substrates. The classical division of the crystallized material into a large grain layer and a fine grain layer is found with these experimental conditions but also we show that a layer with bubbles appears between the two crystallized zones. A comparison with the calculation of temperature leads us to think that crystallization cannot occur if the temperature reached at a given depth is below a temperature Tmin. This temperature may be related to the nucleation rate in a-Si.

With a thermal annealing applied to samples of Al implanted Si (at 300 °C and 2.6 × 1016 ions/cm2), which then contain small plates of hexagonal Si in the {113} planes of the matrix, it is possible to induce precipitation of Al without perturbation of the “{113} defects”. The precipitates, observed and located by TEM and SIMS, are formed of pure Al and present orientation relations with the Si lattice. No interaction is observed between the formations of both types of aggregates. Un traitement thermique applique à des échantillons de silicium implanté à 300 °C avec 2,6 × × 1016 ions/cm2 d'aluminium et contenant par suite des plaquettes de Si hexagonal dans les plans {113} permet de faire précipiter l'Ai sans perturber ces “défauts {113}”. Les précipités observés et localisés en TEM et SIMS sont formés d'aluminium pur et présentent des relations d'orientation avec la matrice Si. On ne constate pas d'interaction entre les formations des deux types d'agrégats.

The heaviest rare gases atoms (Ar, Kr, Xe) implanted at room temperature into metallic matrices tend to precipitate and to form solid crystallized bubbles (or precipitates). Rare gas bubbles are small (a few nanometers) and under high pressure (a few GPa), they have the matrix structure in f.c.c. or h.c.p. metals. However, a systematic study of xenon precipitates in aluminium shows that their structure is not perfectly f.c.c. and that the deviation increases when decreasing fluence. In order to explain our experimental results, we build up an elementary model which assumes the existence of four types of precipitates (variants), each of them is associated with one of {111} family planes.

Dissociation widths of dislocations in silicon submitted to high stress and low temperature (HS/LT) are reported. In the first part of the paper, force systems (glide and climb components) acting on a pre-existing dissociated dislocation loop are analysed in terms of the deformation compression axis K. Then two main force systems are experimentally examined: (i) static cases for which the whole dislocation is at rest while partials are submitted to forces with directions which should result in a narrowing or a widening of the stacking fault ribbon; and (ii) dynamic cases (K = 〈120〉) with very different force systems. In all cases stacking faults have been found to be intrinsic. Climb forces seem to act on friction forces of 30[ddot] partials according as to whether they are positive or negative. Models developed by Alexander to explain the mobility of dislocations in the HS/LT conditions cannot account for our results. It is suggested that point defects could have an important effect on the mobility of partials.

In the search of defect creation by a mechanism involving collective electron excitation, samples of silicon are irradiated by Kr and Xe ions, the eneergies of which were 3.7 and 3.5 GeV, respectively. The damage is investigated using the in-situ resistance measurement on samples piled-up along the beam direetion for the high electronic stopping power range between 3.7 to 14 MeV/μm. A normalization of all the data by the number of displaced atoms per atom resulting from elastic collisions shows that inelastic collisions are ineffieient in the defect creation. Bei der Untersuchung der Defektbildung über einen Mechanismus, der kollektive Elektronenanregung einschließt, werden Siliziumproben mittels Kr. und Xe-Ionen mit Energien von 3,7 bzw. 3,5 GeV beschossen. Der Strahlenschaden wird mit "in-situ"︁-Widerstandsmessungen für den hohen elektronischen Bremskraftbereich zwischen 3,7 bis 14 MeV/μm an Proben gemessen, die entlang der Strahlrichtung aufgestapelt sind. Eine Normierung aller Werte durch die Zahl der verlagerten Atome pro Atom aus elastischen Stößen zeigt, daß inelastische Stöße bei der Defektbildung ineffizient sind.

The Vickers microhardness of Cd x Hg1−xTe alloys has been measured at room temperature as a function of composition and of the nature of the {111} faces for different conduction types. The hardness-composition curve shows a maximum at aboutx = 0.75. On the {111} faces, it has been found that the metal face (A face) is harder than the metalloid face for all studied doping types and is related to the different mobilities of the A(g) and B(g) dislocations. This behaviour is compared with a model previously developed for hardness polarity in GaAs.