Compositional Analysis of Chondritic Sulfide Material: A Test of the Mass-Thickness Approach to Quantitative EDS in the TEM

Abstract

Energy-dispersive X-ray spectroscopy (EDS) is central to the compositional analysis of planetary materials. When coupled to a transmission electron microscope (TEM), EDS can provide both qualitative and quantitative information in the form of false-color maps and as (normalized) elemental abundances, respectively, at scales ranging from the micrometer down to the atomic. Such information is important in planetary science for identifying two-dimensional compositional variations and as an aid to phase identification. Quantitative information is particularly important for comparing material composition to the output of thermodynamic codes as part of the process of reverse engineering the origins and history of planetary materials and parameterizing chemical models of the early solar nebula. Thus, quantitative EDS has been a mainstay tool of the planetary-science community for decades and will continue to be important for analysis of samples we currently have in our collections and those returned by sample-return missions such as Hayabusa2 [1] and to be returned by OSIRIS-REx [2].