Introduction to XAFS: A Practical Guide to X-ray Absorption Fine Structure Spectroscopy

by Grant Bunker

Overview

X-ray absorption fine structure spectroscopy (XAFS) is a powerful and versatile technique for studying structures of materials in chemistry, physics, biology and other fields. This textbook is a comprehensive, practical guide to carrying out and interpreting XAFS experiments. Assuming only undergraduate-level physics and mathematics, the textbook is ideally suited for graduate students in physics and chemistry starting XAFS-based research. It contains concise executable example programs in Mathematica 7. Supplementary material available at www.cambridge.org/9780521767750 includes Mathematica code from the book, related Mathematica programs, and worked data analysis examples. The textbook addresses experiment, theory, and data analysis, but is not tied to specific data analysis programs or philosophies. This makes it accessible to a broad audience in the sciences, and a useful guide for researchers entering the subject.

Product Details

ISBN-13:	9780521767750
Publisher:	Cambridge University Press
Publication date:	01/28/2010
Pages:	270
Product dimensions:	7.00(w) x 9.80(h) x 0.70(d)

About the Author

Grant Bunker is Professor of Physics at the Illinois Institute of Technology. He has over thirty years experience in all aspects of XAFS spectroscopy, from technique development, instrumentation and computation, to applications in biology, chemistry and physics.

Table of Contents

Preface vii

1 Introduction 1

1.1 What is XAFS? 1

1.2 Physics of XAFS 2

1.3 Synchrotron radiation 4

1.4 Purpose of this book 6

2 Basic physics of X-ray absorption and scattering 8

2.1 X-rays 8

2.2 The structure of atoms 9

2.3 Atomic units 11

2.4 Types of interactions 13

2.5 Cross sections 14

2.6 Elastic scattering from free electrons 20

2.7 Elastic scattering from electron distributions 21

2.8 Elastic scattering from atoms with no excitation 24

2.9 Elastic scattering from crystals 26

2.10 Fourier transform of the lattice 28

2.11 Compton scattering from free electrons 32

2.12 Inelastic scattering from atoms 32

2.13 Core-hole lifetime 33

3 Experimental 36

3.1 Requirements for XAFS experiments 36

3.2 X-ray sources 41

3.3 Synchrotron radiation 42

3.4 Beamlines and optics 52

3.5 X-ray detectors 60

3.6 XAFS experiments 80

3.7 Samples 96

3.8 Data acquisition 103

4 Theory 106

4.1 Introduction 106

4.2 Transition rate 107

4.3 Band structure, molecular orbital, clusters 115

4.4 Multiple scattering expansion 118

4.5 Outline of theoretical calculation 120

4.6 EXAFS equation 125

5 Data analysis 134

5.1 XANES 135

5.2 EXAFS 146

5.3 Data fitting 173

6 Related techniques and conclusion 189

6.1 Related techniques 189

6.2 Conclusion 191

Appendix 1 Introduction to Fourier transforms in EXAFS 193

Appendix 2 Cumulants in EXAFS 212

Appendix 3 Optimizing X-ray filters 219

Appendix 4 Reference spectra 232

Appendix 5 X-ray tables 241

References 251

Index 258