Absorption corrections

One of the important corrections is for the absorption of the incident and diffracted x-ray beams as they travel through the sample. Three possible absorption correction methods are:

1. For small absorption corrections, intensity formula, and the effective produced by the direct spline analysis method can be appropriately phase shifted. This method is illustrated by the direct spline analysis of the Cu data presented in Section 5.
2. The absorption correction can be reconstructed from the simultaneous fluorescence measurements. This method is illustrated by the iterative Kramers-Kronig analysis of the Cu and YBa₂Cu₃O_6.6 data presented in Sections 5, 7 and 8.
3. The absorption correction could also be constructed self-consistently using the f'' functions obtained during the iterative Kramers-Kronig analysis of the DAFS signal.

It is important to remember that the absorption signal is different than the DAFS and signals because XAFS weights the sites based on the number of atoms within the unit cell, whereas DAFS weights the sites crystallographically. Thus measurements of the single function are not sufficient to determine the multiple and functions for systems which contain multiple inequivalent sites.