Resonant Anomalous X-Ray Reflectivity

Resonant anomalous x-ray reflectivity (RAXR) makes use of the ‘anomolous’ dispersion in the atomic scattering factor of an atom near its characteristic absorption edge. This allows for the possibility of incorporating element-specific information into the x-ray scattering methods. Both the real (f’) and imaginary (f’’) parts of the scattering factor are modified which are related to each other by Kramers-Kronig relations. The imaginary part of the resonant scattering factor, f’’(E) is proportional to the x-ray absorption near edge structure (XANES) profile that could be measured in x-ray absorption spectroscopy. Consequently RAXR brings together the unprecedented structural sensitivity and interfacial specificity of x-ray reflectivity measurements with the element-specificity and spectroscopic sensitivity of XANES measurements leading to a much more complete understanding of the complex structural and chemical changes of many important interfacial processes.

Reference

Park C., Fenter P. A., Sturchio N. C., and Regalbuto J. R. (2005) Probing outer-sphere adsorption of aqueous metal complexes at the oxide-water interface with resonant anomalous X-ray reflectivity. Physical Review Letters 94(7), 076104.