Calcul de l'effet d'un etat d'interface sur le travail de sorte d'un semiconducteur recouvert d'une couche mince

We carried out a theoretical investigation of the work function of a semiconductor covered with a thin film. We assumed that the layer was also a semiconductor and that there was an interface state. The structure is regarded as a heterojunction in which the space charge may extend over the whole thickness of the layer. Results are given for an example: the Ge/GaAs heterojunction.     

Influence de l'implantation ionique sur l'oxydation du titane par l'oxygene

Ion implantation can lead to great modifications of titanium oxidation at 600°C in oxygen atmosphere. Oxygen short circuit diffusion is enhanced by the ion bombardment of the metal but can be reduced if the amount of the implant exceeds its solubility limit in α-Ti.Kinetic measurements have been performed with Rb, Cs or Ba implanted samples. The results suggest that heavy alkaline implants inhibit the $\text{Ti (+III)}\text{Ti (+IV)}$ oxidation whereas barium decreases the oxygen diffusion coefficient in TiO₂.     

Amelioration des conditions de synthese de l'hydrure de magnesium a l'aide d'adjuvants

Addition of metals or alloys whose hydrides have a high dissociation tension allows a considerable increase of the hydrogenation rate of magnesium. The influence of the nature of the adjuvant and its specific concentration, of temperature and hydrogen pressure on the reaction rate, have been carefully studied. The pressure-composition isotherms have been determined especially when the adjuvant is LaNi₅.     

Minimafios,source d'ions multicharges fournissant des faisceaux d'ions d'aluminium completement epluches

The multiply charged ECR ion source MINIMAFIOS can now be operated in runs of long duration with aluminium ions. Vapor production and ionization are described. Ion CSDs are given. Up to completely stripped Al¹³⁺ ions are produced and identified by the detection of Lyman α and β lines in the X-ray range.     

Les proprietes de transport d'halogenures d'etain divalent

The ionic conductivity of SnF₂ and SnFCl has been studied by the complex impedance method: SnF₂ has electric properties close to those of the fluorine-type β - PbF₂. The fluorine mobility in SnFCl is low in comparison with α - PbF₂ despite similar structures. These features are explained on the base of structural and size considerations.     

一种鼓舞汽车制造业的成套工艺技术——合成材料补充钢材

 长期以来，金属和合成材料在传统的设计方法领域中呈现一种明显的相互竞争的关系．由拜耳公司(Bayer AG)开发并取得国际专利的复合工艺，通过采用各种不同的合成材料来赋予钢材一些特殊的性能．     

Synthese d'une nouvelle famille d'antimoniates de structure grenat

The existence of complex antimonates with the garnet structure is discussed, and a number of such compounds have been effectively synthesized and investigated by X-ray diffractometry and vibrational spectroscopy. The infrared spectra confirm the predicted octahedral coordination of Sb⁵⁺ cations.     

Caracterisation d'oxydes de cuivre par spectrometrie d'absorption X

The devolopment of new physical methods as photoelectron spectroscopy (ESCA), X-ray emission and absorption spectroscopies is needful to characterize the chemical bonding in materials like Cu_0.5Fe_2.5O₄ and CuMn₂O₄.The K-absorption edges of copper in oxides CuMO₂ and CuM₂O₄ have been studied with a view to further analytical applications.     

Materials for the 80's and 90's

The factors governing the application of new materials and manufacturing process are reviewed and the criteria for successful exploitation are described. It is shown that developments should be targetted on specific components but there should preferably be several of these in different industries to reduce the risk and maximise the benefits of success. Composite materials — combinationsof two or more material types are believed to have the best future provided that the necessary production and quality control techniques can be developed.     

Publisher's note

Sea ice pressure ridge sail heights and the dimensions of ice blocks that comprised the sails were measured for 30 ridges in April, 1980. The ridges were located from 30 to 200 km offshore in the Prudhoe Bay, Alaska region. Sail height was found to be a function of the thickness of the ice in the ridge. A reasonable relationship shows that height is dependent on the square root of block thickness. The data also verify that the ratio of sail height to ice block thickness is much larger for ridges composed of thin ice than for those composed of thick ice. Ridge width and cross-sectional area are also found to be related to block thickness. For the largest blocks in the ridge, block surface area is related to thickness squared, as would be expected from plate deflection theory. Examination of lateral variation of height and width along the ridge shows an expected large variation, particularly with height. No geographic variations of individual pressure ridge morphology were discernible from these data, but a laser profile taken during the study period shows that the mean heights and numbers of ridges decrease as the distance from the coast increases.     

Anisotropie de la decomposition d'un solide. II-mise en evidence d'un gradient thermique dans la phase solide a l'aide d'un thermographe infra-rouge

Monocrystalline platelets of pentahydrate Copper sulfate are submitted to temperature and pressure conditions such that they cause this salt to be converted into a trihydrated salt. Thermal equilibrium of these platelets is ensured before the reaction starts. Temperature is recorded as moving away from the superficial domain undergoing conversion, by means of an I.R. scanning camera fitted with a cooled detecting device. The occurence of a thermal gradient from the reactive solid-solid interface can, thus, be shown. It seems, therefore necessary to take into account the physical properties of the crystal, which are involved in the occurence of thermal gradients in the solid, to explain the anisotropy of this interface displacement during a conversion where a gas is removed.     

Etude comparee des proprietes electriques des hexaborures d'europium et d'ytterbium

Electrical conductivity and Seebeck coefficient of semiconducting EuB₆ and YbB₆ have been investigated and compared. The results are discussed in terms of a band model in which the conduction band is the 5d or 6s band of the rare-earth sublattice.