A Further Improvement in the Gaussian ϕ(ϱ) Approach for Matrix Correction in Quantitative Electron Probe Microanalysis

Abstract

An improved correction model for quantitative electron probe microanalysis, based on modifications of the Gaussian ϕ(ϱ) approach, originally introduced by Packwood and Brown, is presented. The improvements consist of better equations for the input parameters of this model which have been obtained by fitting to experimental ϕ(ϱ) data. The new program has been tested on 627 measurements for medium to heavy elements (Z>11) and on 117 carbon measurements with excellent results: an r.m.s. value of 2.99% in the former case and 4.1% in the latter. Finally the new program has been compared to five other current correction programs which were found to perform less satisfactorily.

Structure and composition analysis of the phases in the system Th-Pd-B-C containing superconductors with Tc = 14.5 K and Tc = 21 K

“…As reference materials are used the ThPd3 phase present in sample 1 as Th and Pd standard, pure B and pure C (C lamellae in Fe3C). The concentrations were calculated using the modified ~(pz) approach [9 ].…”

Progress in the Characterization of Layered Structures by X-Ray Microanalysis

“…This is largely due to the fact that the underlying approximation.in the ZAF technique, absorption along a fixed path length related to the mean X-ray generation depth, is replaced by a more exact integration over the entire depth range. The validity of various 0(pz) models has been assessed with respect to an extensive experimental data base [1][2][3], confirming that results are generally superior to those obtained by ZAF calculations, particularly for light element analysis.…”

“…The detection limit is generally 0 .1 Ag cm-2 [3]. Internal where Rc is the mass depth at which the equations (1) and (2) are equivalent, Rm is the mass depth at which the function 0(pz) reaches its maximum and Rx is that at which it vanishes.…”

A characteristic fluorescence correction factor for use in electron probe microanalysis. II. Evaluation of experimental results and comparisons

“…that of the modified Gaussian distribution. This description was first proposed by Packwood and Brown [38] and has been further elaborated by several authors [5,[39][40][41][42][43] :…”

“…Generally [5,[38][39][40][41] the expression of Love et al [44] is used for the quantification of this parameter; some recent models, though, employ new quantifications [26,42], since the formula given by Love et aL [44] Figure 3 shows the percental deviations of the absorption terms of Wittry [46], Reed [1] (taken from Castaing [33]), Criss [47] and Heinrich [8], respectively, from those calculated in the present paper for a K~K excitation. The exciting element is nickel, and the excited elements have atomic numbers ranging from Z = 18 to Z = 26.…”