The influence of the focusing effect on the X-ray absorption fine structure above all the tungsten L edges in non-stoichiometric tungsten oxides

The role of multiple-scattering contributions in the formation of the X-ray absorption fine structure (XAFS) above tungsten L edges is discussed for the non-stoichiometric tungsten oxides WO 3-x . It is found that the presence of linear or near-linear atomic chains in the WO 3-x crystal structure leads, due to the focusing effect, to a strong increase in the XAFS amplitude. which results in an admixture of the L 2 -edge XAFS With the XAFS above the L 1 edge.