title: Improving Signal-to-Noise Ratio in Scanning Transmission Electron Microscopy Energy-Dispersive X-Ray (STEM-EDX) Spectrum Images Using Single-Atomic-Column Cross-Correlation Averaging.
abstract: Acquiring an atomic-resolution compositional map of crystalline specimens has become routine practice, thus opening possibilities for extracting subatomic information from such maps. A key challenge for achieving subatomic precision is the improvement of signal-to-noise ratio (SNR) of compositional maps. Here, we report a simple and reliable solution for achieving high-SNR energy-dispersive X-ray (EDX) spectroscopy spectrum images for individual atomic columns. The method is based on standard cross-correlation aided by averaging of single-column EDX maps with modifications in the reference image. It produces EDX maps with minimal specimen drift, beam drift, and scan distortions. Step-by-step procedures to determine a self-consistent reference map with a discussion on the reliability, stability, and limitations of the method are presented here.
authors.affiliation: Department of Chemical Engineering and Materials Science,University of Minnesota,Minneapolis,MN 55455,USA.
authors.forename: Jong Seok
authors.identifier: 0000-0002-5570-748X
authors.initials: JS
authors.lastname: Jeong
authors.affiliation: Department of Chemical Engineering and Materials Science,University of Minnesota,Minneapolis,MN 55455,USA.
authors.forename: K Andre
authors.initials: KA
authors.lastname: Mkhoyan
keywords: STEM-EDX; averaging; cross-correlation; image processing; subatomic precision