Diagnostic Nano-Analysis of Materials Properties by Multivariate Curve Resolution Applied to Spectrum Images by S/TEM-EELS

Abstract

The data cube of spectrum imaging (SI) by scanning TEM (STEM) and electron energy-loss spectroscopy (EELS) or energy-filtering TEM (EF-TEM) can be treated as the two-dimensional data array, each row corresponding to the EELS spectrum at a specific position. A multivariate curve resolution (MCR) technique can then apply to the dataset, which decomposes the set of spectra into the product of the constituent pure spectral components and their corresponding relative composition matrices without any reference spectra. This method allows us to provide a two dimensional spatial distribution map of different chemical states incorporated even when the multiply spectra overlap with one another. Several application examples are presented.