Local Thermodynamic Measurements of Dilute Binary Alloys using XAFS

PhD Thesis
Matthew Newville
University of Washington, 1995

Table of Contents

1. Introduction. 1
   1. Impurities in Dilute Binary Alloys and Melting
   2. Thermodynamics and Local Atomic Structure
   3. Measurements of the Local Atomic Structure of Binary Alloys
   4. Mossbauer Measurements on Dilute Binary Alloys
   5. XAFS Measurements on Dilute Binary Alloys
   6. The Goals of This Work
2. X-ray Absorption Fine Structure 11
   1. X-Ray Absorption
   2. Simple Development of the XAFS Equation
   3. A Few Important Points Skipped Over in the Above Discussion
   4. Effect of Local Structure on XAFS: The Cumulant Expansion
3. XAFS Experiments 28
   1. Collection of XAFS Data
   2. XAFS Measurements at Low and High Temperature
   3. Sample Preparation
4. Analysis of X-ray Absorption Fine Structure Data 42
   1. The Information Content of XAFS Data
   2. The XAFS Fourier Transform
   3. The Isolation of chi(k)
   4. Theoretical Standards in XAFS Analysis
   5. feffit: Using feff in R-space for XAFS Data Analysis
   6. Goodness of Fit and Estimation of Uncertainties
   7. An Example Fit: Pure Cu at 10K
5. The Structural and Thermodynamic Properties of an Anharmonic Potential 73
   1. The Cumulants for a Slightly Anharmonic Potential
   2. The Thermodynamics for a Slightly Anharmonic Potential
6. XAFS Analysis of Pure Ag and Au 81
   1. The XAFS of Pure Ag
   2. Multiple Scattering Analysis of Ag at 80K
   3. High Temperature Analysis of Ag XAFS Data
   4. Thermodynamic Parameters for Ag from XAFS Analysis
   5. High Temperature Analysis of Au XAFS Data
   6. Thermodynamic Parameters for Au from XAFS Analysis
7. Embedded-Atom-Model Calculations for Pure Ag 108
8. XAFS Analysis of Impurities in Ag 112
   1. 5% Ga in Ag
   2. 2.5% Ga in Ag
   3. 5% Sn in Ag
   4. 5% Au in Ag
   5. Summary of Results for Impurities in Ag
9. XAFS Analysis of Impurities in Au 146
   1. 2% Sn in Au
   2. 5% Ag in Au
   3. Summary of Results for Impurities in Au
10. Conclusions 163
    1. Suggestions for Future Work

• Bibliography 169
• Appendix A: A Complex Set of Constraints in FEFFIT 180

[ CARS | Advanced Photon Source | Argonne Natl Lab | Univ of Chicago | UWXAFS Project ]