Resampling SEM-EDS Maps to Characterize the Length Scale of Elemental Heterogeneity

Abstract A new method to quantify elemental heterogeneity as a function of length scale was developed based on resampling SEM-EDS element maps. The average X-ray intensity per pixel is calculated for non-overlapping domains of a given size across an element map. The standard deviation of these averages is plotted as a function of domain size. The method was applied to a suite of ceramic samples to compare heterogeneity as a function of raw materials and milling. The resulting data effectively tracked heterogeneity as a function of grain-size reduction by milling and would also be useful for tracking the degree of mixing. Calculated results are affected by the composition of the phases in the sample and the bulk composition, so care must be taken when comparing samples that differ in these characteristics.