AVS 57th International Symposium & Exhibition
    Applied Surface Science Thursday Sessions
       Session AS1-ThM

Paper AS1-ThM6
Multivariate Analysis of NEXAFS Spectrum Images

Thursday, October 21, 2010, 9:40 am, Room Cochiti

Session: Advanced Automation and Data Processing
Presenter: J.A. Ohlhausen, Sandia National Laboratories
Authors: J.A. Ohlhausen, Sandia National Laboratories
M.T. Brumbach, Sandia National Laboratories
C. Jaye, NIST
D.A. Fischer, NIST
E. Principe, Synchrotron Research, Inc.
P. Sobol, Synchrotron Research, Inc.
Correspondent: Click to Email

Multivariate analysis methods have been applied to Near Edge X-ray Absorption Fine Structure (NEXAFS) spectrum images acquired at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratories (BNL). NEXAFS has typically been a large spot technique, but with the new imaging system on U7a at NSLS, spectrum images can now be acquired. These spectrum images can be processed univariately, but many issues confound the analysis. Issues include overlapping peaks, broad spectral features, poor contrast, non-zero backgrounds and unique synchrotron-related data artifacts. We will discuss these issues and their implications to successful multivariate analysis. Strategies for removing non-uniform illumination and time-dependent illumination decay will be shown. Additionally, the energy of secondary electrons can be filtered so that the depth of analysis is varied, leading to depth and spatially-resolved (3D) chemical information. We will demonstrate the multivariate analysis of data acquired by this technique as well.

Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.