An investigation of electron probe microanalysis corrections in nickel - cobalt alloys

Abstract

Homogeneous nickel - cobalt binary alloys were analysed in the electron probe microanalyser to determine the magnitude of the atomic number and Kβ-Kα secondary fluorescence corrections. In these alloys, the atomic number effect is due almost entirely to the ionization-penetration factor. A relative error of 4-6% between the nickel intensity ratios and the true composition was found in the high cobalt alloys. This error was an additional 2-3% greater than that predicted by the Philibert and Tixier atomic number correction. When used with the Philibert and Tixier correction none of the well-known expressions for the mean ionization potential were able to account for the difference between the experimental and predicted values. Secondary fluorescence of Co Kα radiation by Ni Kβ radiation was significant in the high nickel alloys, causing relative errors of up to 4% and overriding the atomic number effect. The Reed fluorescence correction did not completely correct for this error.