An improved absorption correction based on a Gaussian ionization distribution model for electron probe microanalysis

Abstract

The electron range equation R, employed in a Gaussian absorption correction, is optimized making use of f(χ) values which were calculated from ionization distributions determined experimentally by Brown and Parobek. A new expression of R[ R = (1 + 2 h) (1 + h )2.59 × 10 −5( E 1.3 0 − E 1.3 c )] g cm −2 is proposed in this paper. The absorption correction using the new electron range equation R is applied to oxygen determination in several silicates and sulfates with greater accuracy than other methods. This equation also predicts one of the most accurate mean depths of ionization at an accelerating voltage of 25 kV for Zn and Cd tracers in Al, Cu, Ag and Au matrices.