X-Ray Spectrometry 

About: X-Ray Spectrometry is an academic journal published by Wiley. The journal publishes majorly in the area(s): X-ray fluorescence & Fluorescence spectrometry. It has an ISSN identifier of 0049-8246. Over the lifetime, 2798 publications have been published receiving 35878 citations. The journal is also known as: XRS. X-Ray spectrometry & Xray spectrometry.

Assignment of pre‐edge peaks in K‐edge x‐ray absorption spectra of 3d transition metal compounds: electric dipole or quadrupole?

Abstract: The characteristics of pre-edge peaks in K-edge x-ray absorption near edge structure (XANES) spectra of 3d transition metals were reviewed from viewpoints of the selection rule, coordination number, number of d-electrons, and symmetry of the coordination sphere. The contribution of the electric dipole and quadrupole transition to the peaks was discussed on the basis of the group theory, polarized spectra, and theoretical calculations. The pre-edge peak intensity for Td symmetry is larger than those for Oh symmetry for all 3d elements. The intense pre-edge peak for tetrahedral species of 3d transition metals is not due to 1s–3d transition, but transition to the p component in d–p hybridized orbital. The mixing of metal 4p orbitals with the 3d orbitals depends strongly on the coordination symmetry, and the possibility is predictable by group theory. The transition of 1s electron to d orbitals is electric quadrupole component in any of the symmetries. The d–p hybridization does not occur with regular octahedral symmetry, and the weak pre-edge peak consists of 1s–3d electric quadrupole transition. The pre-edge peak intensity for a compound with a tetrahedral center changes as a function of the number of 3d electrons regardless of the kind of element; it is maximized at d0 and gradually decreases to zero at d10. The features of pre-edge peaks in K-edge XANES spectra for 4d elements and the L1-edge for 5d elements are analogous with those for 3d elements, but the pre-edge peak is broadened due to the wide natural width of the core level. Copyright © 2008 John Wiley & Sons, Ltd.

Analysis of X-ray spectra by iterative least squares (AXIL): New developments

Abstract: The functionality of the computer package AXIL (Analysis of X-ray spectra by Iterative Least squares), suitable for the evaluation of energy-dispersive X-ray spectra, has been extended in a number of ways. First, a background modelling algorithm, based on the use of mutually orthogonal polynomials was introduced to replace the linear or exponential polynomials employed previously. Second, the Gaussian photopeak model employed in previous versions of the program was extended to include the non-Gaussian parts of the characteristic peaks and related background contributions. Both innovations are shown to improve the performance of the spectrum evaluation procedure. Third, the user-friendliness of the evaluation program was enhanced (a) by allowing a PC plug-in MCA card to be directly controlled from within the program and (b) by extending the command-interface to allow for repeated execution of series of commands by means of control loops. A brief description of these changes is given; as an application, the accurate evaluation of micro-XRF images is discussed.

A simple method to evaluate the matrix effects in X-Ray fluorescence analysis

Abstract: In X-ray fluorescence analyses, the matrix effects can be evaluated by computing appropriate coefficients. Utilising powder pellets of samples artificially prepared, a method for computing the matrix effects coefficient of H2O, Na2O, MgO, Al2O3, SiO2, K2O, CaO, TiO2, Fe2O3 for the analytical lines of thirteen elements: vanadium, chromium, nickel, copper, zinc, gallium, rubidium, strontium, zirconium, barium, lanthanum, cerium and lead is described. The computed coefficients have been used to analyse six international rock standards (the U.S. Geological Survey Standards: G-2, GSP-1, AGV-1, BCR-1, PCC-1, DTS-1).

X‐ray fluorescence spectrometry in art and archaeology

Abstract: This paper presents examples of analyses by x-ray fluorescence (XRF) spectrometry in art and archaeology, including pigments in paint layers and illuminated manusripts, of iridescent glasses and of medieval coins. Theoretical aspects of information depths and shielding effects in layered materials are discussed. Element maps were experimentally obtained by a specially designed x-ray spectrometer (1 × 1 mm pixel resolution) and by electron-excited XRF (electron microprobe). Copyright © 2000 John Wiley & Sons, Ltd.

L shell fluorescence yields and coster—kronig transition probabilities for the elements with 25 ⩽ Z ⩽ 96

Abstract: The values of Li sub-shell fluorescence yields (ωi) and Coster–Kronig transition probabilities (fij) were evaluated using radiative and non-radiative transition rates based on the relativistic Dirac–Hartree–Slater (RDHS) model for all the elements in the atomic number range 25 ⩽ Z ⩽ 96. The values of the Coster–Kronig-corrected fluorescence (vi) and average L shell fluorescence (ϖL) yields were also evaluated and least-squares fitted to obtain the polynomials representing them as a function of atomic number.