High efficiency core-loss EELS analyzing from the viewpoint of chemometrics

Abstract

Electron energy–loss spectroscopy (EELS) equipped on a modern scanning transmission electron microscope is a powerful high resolution elemental analysis technique. However, the conventional method of extracting elemental information quantitatively from EELS spectra is non-trivial. In this article we tried to interpret EELS data from the viewpoint of chemometrics. An EELS spectrum image collected from a vicinal SiC/SiO2 interface was employed as an example. By analyzing the EELS data with sophisticated chemometrics methods, chemical components and elemental ratios of C/Si and O/Si across the interface were derived. Compared with conventional EELS analysis, the chemometrics methods gave more reliable and accurate results with higher calculation efficiency. The chemometrics analysis confirmed that the transition from SiC to SiO2 was chemically sharp, and the transition layer in the vicinal interface was a linear combination of SiC and SiO2. Chemometrics analysis can be a fast and robust complementary method for EELS analysis.