J.L. Pouchou's scientific contributions

Publications (21)

Chapter
The use of soft X-rays in microanalysis is illustrated by several new practical examples, concerning the K lines of the ultra-light elements, and the L lines of medium-Z elements that can be used for near-surface analysis and in situations where eliminating the secondary fluorescence emission is of interest. Some of the specific problems of the sof...
Article
The paper gives an overview of the problems of Standardless analysis of bulk specimens by energy dispersive spectrometry (EDS) in scanning electron microscopes (SEM). The interest is concentrated on the present (and future) developments. The influence of the fluorescence excited by the continuum is discussed. Some improvements are proposed for the...
Article
This paper presents a description of the state of the art methodology and software for the application of x-ray microanalysis to thin surface layers and more generally to the characterization of stratified specimens. The sensitivity of the technique to near-surface segregation is demonstrated. Some emphasis is given on the φ(ϱz) function (the distr...
Article
The ϕ(ρz) models developed during the recent years (Gaussian, PAP, XPP) have been shown by several authors to improve significantly the capability of quantitative x-ray microanalysis, mainly in the field of light elements, tilted specimens, and layered specimens. An increasing number of users is now able to take advantage of these models, since som...
Chapter
For about 20 years, quantitative analysis of homogeneous microvolumes has been performed with the aid of correction models which transform into mass concentrations C A the ratio k A between the emerging intensities from the specimen and a standard obtained for a characteristic line of element A:
Article
Extensive work has been done during the last decade to develop new models able to improve the performance of data reduction procedures 1n quantitative x-ray microanalysis. Some of them are now successfully used as routine tools in microprobe work, and allow to analyze accurately light and ultra-light elements and to characterize layered specimens....
Article
The application of the XPP model for φ(ρz) curves (X-ray generation curves) to energy dispersive X-ray analysis in the scanning electron microscope is discussed. The basic model and its addition features are described. Preliminary assessments of the implementation of the model in the KEVEX system are reported.
Article
Quelques applications d'un nouveau modèle de calcul en microanalyse, combinant les effets d'absorption et de numéro atomique, sont présentées. Un accent particulier est mis sur l'amélioration notable des corrections d'absorption, ainsi que sur la possibilité d'aborder quantitativement l'étude d'échantillons chimiquement inhomogènes en profondeur. S...
Article
Quelques applications d'un nouveau modèle de calcul adapté à l'étude quantitative d'échantillons inhomogènes en profondeur sont présentées. Some applications of a new model allowing quantitative study of in-depth heterogeneous samples are presented.
Article
The model prepared in Part I for quantitative analysis of homogeneous samples, is extended to in-depth analysis of heterogeneous samples. Several examples illustrate the performance of the method, particularly for layered sample studies: thickness determination of surface films ranging from a few micrograms per square centimeter to about 1 mg/cm**2...
Article
A new treatment of absorption and atomic number effects is presented for computing the characteristic X-ray intensities emerging from a homogeneous sample subjected to electron bombardment. The basic aspects of quantitative microanalysis are briefly recalled, and the presently available correction models are reviewed. The new formulation is then ap...

Citations

... Measured elements were counted for 10 s on peaks and 5 s background on either side of the peak. Peaks were calibrated by measurements of standards (natural minerals and synthetic oxides), following the PAP corrections method of Pouchou (1985). ...
... This can be done by means of calibration techniques obtained from EPMA and/or RBS measurements (see, e.g., Hunger [90] and references therein; Kang et al. [95]) or Monte Carlo simulation results [96,97]. Alternatively, thin films can be analyzed using EPMA programs suitably extended to describe the thin film geometry [91,98,99] or other computational approaches such as the invariant embedding method [100]. Among the existing standalone thin-film programs, there is STRATAGem [101], GMRfilm [102], and BadgerFilm [103]. ...
... Several thin sections were prepared from the sample and examined by optical microscopy (in The peak counting times were 20 seconds with the exception of Se and S (30 seconds), with the background counted for half of that time, once on each side of the peak. The ZAF corrections followed the PAP procedure (Pouchou and Pichoir 1984;Pouchou and Pichoir 1985). Reference materials are natural and synthetic CdSe (for Se), PbTe (for Pb and Te), pyrite (for S and Fe), stibnite (for Sb), silver (for Ag), bismuthinite (for Bi), chalcopyrite (for Cu), pentlandite (for Ni), and cobalt (for Co). ...
... The acquisition time for each element was 40 s. We used natural standards and the PAP algorithm (Pouchou and Pichoir, 1984) for converting the signal into the element concentration (wt %). ...
... The analytical standards were apatite (P), GaAs (As), stibnite (Sb), orthoclase (Si, K), TiO 2 (Ti), Al 2 O 3 (Al), fayalite (Fe), forsterite (Mg), wollastonite (Ca), pure Cu (Cu), willemite (Zn), PbCO 3 (Pb), and LiF (F). Raw intensity data were corrected using a PAP matrix correction (POUCHOU & PICHOIR 1984). ...
... Synthetic wollastonite (Ca), natural olivine (Fe in silicates, Mg, Si), hematite (Fe in oxides, metals, and sulfides), corundum (Al), natural ilmenite (Mn), fluorapatite (P), orthoclase (K), sphalerite (S), synthetic NiO (Ni), synthetic Cr 2 O 3 (Cr), and albite (Na) were used as standards. A matrix correction was performed by using the PAP procedure (Pouchou and Pichoir 1984). ...
... Duncumb & Statham (2002) have shown the benefits of using X-ray spectrum simulations for the interpretation of EDS X-ray spectra at low energies, where on top of the mentioned effects there are the problems of a sloping background and a large change of detector efficiency. In the case of the transition elements, both the emission and absorption of X-rays are still poorly understood when they originate from electron transitions involving the partially filled 3d shell (Pouchou, 1996). This is the case, e.g. for the most intense and widely used Lα (transition M5-L3) and Lβ (transition M4-L2) lines. ...
... Standards used were a combination of natural minerals for Na (jadeite), Mg (olivine), Al (corundum), Ca (wollastonite), Si (fayalite) and Ti (rutile); synthetic compounds for Ti and Mn (MnTiO3), P (ScPO4), K (KBr), Fe (FeO), Ni (NiO2) and pure metals (Co). All data were matrix-corrected using the Cameca version of the PAP PhiRhoZ programme after [29,30]. ...
... Selected back-scattered images of zircons from the Diorite, Monzodiorite, Mafic Granodiorite and Biotite Microgranite shown in Fig. 4. Selected back-scattered images of zircons from the Early Dyke, Southern Porphyry and Late Dyke shown in Fig. 4. U 2 O 3 . Data reduction was done using the PAP procedure (Pouchou and Pichoir, 1984). ...
... A counting time of 20 s was used for the measurements. The concentration of each element was calculated from the ratios between intensity in the specimen and in the standard using the PAP model [23]. ...