Absorption correction in electron probe microanalysis

Abstract

The absorption correction factor f(χ) is calculated by using an empirical equation based on a new shape of the x‐ray depth distribution function Φ(ρz). It assumed that Φ(ρz) increases firstly linearly with the depth ρz up to the depth ρzm at which the function Φ(ρz) reaches its maximum value Φm, and subsequently the function Φ(ρz) decreases exponentially with increasing ρz. The proposed f(χ) equation is a function of the parameters ρzm, Φm and the mean depth of x‐ray production ρz. Based on Monte Carlo calculations, the variation of these parameters with the target atomic number Z, the incident electron energy E0 and the critical energy Ec was studied and empirical expressions were deduced. The calculated parameters were compared with experimental results. The factor f(χ) was calculated and compared with some measurements. The comparison gives an RMS error of 1.88%. The proposed equation was applied to 680 microanalysis data (including light elements). The results gave a relative deviation of about 3%, compared with 4.27% obtained by the quadrilateral model. For high absorbing systems (absorption factor ≤0.5), the present model gave an RMS error of 4.72% compared with 8.18% obtained by the quadrilateral model.

An accurate computer correction program for quantitative electron probe microanalysis

“…Same as Fig. 3 but on the Sewell's data base [34] [30] Bastin [30] Bastin [30] Bastin [30] a,b,c The results were taken from [5], [10], [15] respectively. …”