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 fro m single-crystal sapphire has been recorded by measuring the total-ele ctron yield and x-ray-fluorescence yield with synchrotron radiation. T he edge structures up to 11 eV from the absorption edge are assigned i n terms of the transitions of Al 2p electrons to empty levels using mo lecular-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 neighbo ring atoms as predicted by the multiple-scattering model.