Atom probe characterization of isotropic spinodal decompositions: spatial convolutions and related bias
Résumé
The present study aims at characterizing the amplitude of chromium concentration fluctuations which occur in the spinodally decomposed ferrite phase of a duplex stainless steel. Measured amplitudes are shown to be dependent on both the value of the analysis diameter and the sampling depth as compared with the characteristic lengths of concentration fluctuations. A theoretical model has been designed in order to quantify this dependence. It takes into account axial smoothing, associated with depth sampling, and radial convolution, related to the analysed area which have been studied as a function of different analysis conditions. Optimized analysis parameters are deduced and the corresponding attenuation factor, relative to amplitude measurement, is calculated. \textcopyright 1991.