Correlation between interatomic distances and the x-ray-absorption near-edge structure of single-crystal sapphire

The high-resolution Al L-edge x-ray-absorption near-edge structure from single-crystal sapphire has been recorded by measuring the total-electron yield and x-ray-fluorescence yield with synchrotron radiation. The edge structures up to 11 eV from the absorption edge are assigned in terms of the transitions of Al 2p electrons to empty levels using molecular-orbital calculations. The post-edge features between 11 and 60 eV above the Al L₂₃ absorption edge were found to correlate very well with the interatomic distances from the absorbing atom to its neighboring atoms as predicted by the multiple-scattering model.