J. Phys. IV France 7 (1997) C2-151-C2-152
The Amplitude Reduction Factor in EXAFSM. Roy1, S.J. Gurman2 and G. van Dorssen3
1 Department of Physics, University of Leicester, Leicester LE1 7RH, UK
2 Department of Physics, University of Leicester, Leicester LE1 7RH UK
3 CLRC Daresbury Laboratory, Warrington WA4 4AD, UK
The amplitude reduction factor so2(k) is usually treated as an empirical parameter in EXAFS data analysis, although a few values have been calculated . We present here the results of a simple model calculation that gives accurate values of so2(k) for all absorption edges of all free atoms. The method is based on the use of Slater orbitals and the Sudden Approximation. We also calculate so2(k) using the Tight-Binding model in order to estimate any variation in the amplitude reduction with chemical environment. We find that so2(k) lies between 0.65 and 0.80 for all edges of use in EXAFS and has a characteristic dependence on atomic number. The calculated values are found to agree with a wide range of experimental data.
© EDP Sciences 1997