Theoretical influence coefficients for correction of matrix effects in x‐ray fluorescence analysis of intermediate‐thickness samples

Abstract

Theoretical influence coefficients for x-ray fluorescence analysis of intermediate-thickness samples isproposed. The algorithm, derived from the Sherman equation, corrects simultaneously both absorption and enhancement effects in specimens with various thicknesses. The coefficients take into account all matrix elements, hence they have to be calculated using an iterative approach. Nevertheless, if matrix diversification is limited, the coefficients can be treated as constants for given mass per unit area of the specimen. Then the iteration can be avoided and calculations are simple and fast. The dependence of the influence coefficients on matrix composition and sample thickness is discussed. The validity of the proposed algorithm was checked with certified geological materials, four-element polycrystals and ferroelectric ceramics using wavelength-dispersive x-ray spectrometry.

Determination of thickness and composition of thin films by x‐ray fluorescence spectrometry using theoretical influence coefficient algorithms

“…The coefficients a i , c i and˛i j , in parentheses, depend on the total matrix composition and on the specimen thickness (this dependence was discussed in the previous paper 11 ). Nevertheless, if concentration and thickness ranges are limited, the coefficients can be treated as constants.…”

“…The proposed algorithms can also be applied to thickness determination of pure element films. Then, the analysis does not require iteration, and thickness can be calculated from Eqn (11). Figure 5(a) presents experimental data (tungsten target x-ray tube operated at 45 kV, 1 D 66°and 2 D 35°) for Cu films (thickness from 535 to 16 730Å i.e.…”

“…1 -8 Review of matrix correction methods applied in analysis of intermediatethickness samples including emission-transmission method and methods based on the use of scattered primary radiation is presented in Ref. 9. In the previous papers, influence coefficient models deduced from the Sherman equation were proposed: 10,11…”

Quantitative X-ray fluorescence analysis of samples of less than ‘infinite thickness’: Difficulties and possibilities

“…In the next paper, the theoretical influence coefficient algorithm for intermediate-thickness samples was proposed [99]:…”

“…The influence coefficients in the algorithm [99] are calculated directly from theory using effective values of mass attenuation and photoelectric absorption coefficients if polychromatic excitation is applied. In Ref.…”