Photon Interference X-Ray Absorption Fine Structure

We report about a fine structure in x-ray absorption spectra, named photon interference x-ray absorption fine structure (pi XAFS). pi XAFS is due to the interference of x-rays inside the sample and extends across absorption edges. Using a platinum foil pi XAFS was measured in a high precision absorption experiment. Excellent agreement with a theoretical pi XAFS simulation is achieved in the energy range for above an absorption edge where photoelectron XAFS is negligible. pi XAFS provides a method for determination of atomic structure on short- and long-range order scale.