[en] A part of proceedings of the eight international vacuum congress, on the nuclear energy and research, is included into thirty selected communications

[en] XPS and AES are very similar with regard to physical laws except ionisation process. Up to now, the main obstacle to a common approach was instrumentation: apparatus, mainly analysers, were too different. New systems provide both kind of spectra. The aim of this paper is to help users in the duality and complementarity of these techniques

[en] The primary electron bombardment induces the emission of back scattered or secondary electrons. Their intensity is high against that corresponding to Auger electrons. This is why Auger spectrometry extended as from 1967 only, when Harris finalized a system of energy modulation of the primary electron beam making it possible to obtain on the derived curve dN(E)/dE = f(E) a satisfactory signal to background ratio for a primary electron beam intensity in the vicinity of a microampere. It is the value of this signal to background ratio that limits the sensitivity of the Auger spectrometric system: 0.1 to 1% according to the elements

[en] Auger electron spectroscopy is a powerfull method for identification of elements who are in the first layers near the surface. Quantitative approach needs the finest knowledge of every physical parameters involved in the expression of Auger current: interactions of primary electron beam with target, backscattering, ionisation cross section, Auger emission, and escape depth. Depth profile analysis by combination of Auger electron spectroscopy with ion beam sputtering brings its own incertainties but, in this field also, much progress has been achieved recently

[en] Electrostatic effects are usually observed at the interface of thin aluminium films deposited on polypropylene substrates during depth profiling analysis by Auger electron spectroscopy (AES). Charging build up is characterized by energy shifts of Auger spectra towards higher kinetic energies. These insulating layers (10 to 20 nm) are partially or totally eliminated when the polymer is, prior to the metallization process, submitted either to low pressure (argon, nitrogen or ammoniac) plasma or to inert ion etching treatments. A lowering of oxygen and alumina contents at interfaces and an improved adhesion behavior were simultaneously noted. With Al deposits performed in UHV conditions onto a sputter cleaned substrate: a graphitic-like layer was probably created which ensures the complete removal of the electric charges during analysis at the Al/'polymer' interface, where a direct chemical bonding Al-C was displayed by AES. (Author). 8 refs., 2 figs

[en] The decarburization kinetics of molybdenum with different carbon contents has been studied by ultra-high vacuum techniques (quadrupole mass-spectrometry) over a wide range of temperatures (1240-1920 deg C). Plane sheets and cylindrical samples are heated under some 10^-6 torr O₂. The outgassing flow of CO produced as a function of time is controlled by C diffusion. The reactions kinetics allows to calculate the diffusion constant and the solubility of carbon in molybdenum for different temperatures

[en] The kinetics of decarburisation of molybdenum and TZM have been studied by quadrupole mass spectrometry over the temperature range 1260-2010⁰ C. Flat and cylindrical samples were heated under a few 10^-6 Torr 0₂. The outgassing flow of the carbon monoxide product as a function of time is controlled by the diffusion of carbon. Alloying with titanium and zirconium (TZM alloys) reduces the diffusion of carbon but increases its solubility below 1700⁰C. The decarburisation is accompanied by internal oxidation which does not appear below 2000⁰C in molybdenum. Anomalies in the diffusion of carbon can be attributed to the carbon becoming dissolved in the precipitated titanium oxide. (author)

No abstract available

[en] Auger first experiences in 1923 and thesis in 1926 on photoelectrons with a Wilson chamber are shortly presented. The two related techniques, Siegbahn XPS (X-ray Photoelectron Analysis) and Auger AES (Auger Electron Spectroscopy), are compared for surfaces analysis with advantages and disadvantages. (A.B.). 13 refs., 3 figs

[en] Above 1000⁰C molybdenum-base alloys containing small additions of titanium and zirconium (TZM, TZC) exhibit internal oxidation during decarburization by oxygen (at approximately 10^-5 Torr). Selective precipitation of oxides occurs superficially between 1150 and 1350⁰C for titanium oxide and from 1350 to 1600⁰C for zirconium oxide. In the same temperature range alloying elements segregate with oxygen towards the external surface and promote precipitation. When the diffusion rates of titanium and zirconium become lower than the volatilization rates of the oxides TiO and ZrO, precipitation and segregation disappear (T > 1600⁰C). Bulk precipitation takes place in the alloys (1300 - 1850⁰C). Oxygen permeation is thermally activated for the two precipitated phases. Precipitation is deeper and larger in grain boundaries where alloying elements also segregate. Surface and grain boundary enrichment produced by titanium and zirconium segregation gives a heterogeneous oxide dispersion, especially for zirconia, which seems detrimental for the ductility of the recrystallized materials. (Auth.)