M 3,2-edge x-ray absorption near-edge structure spectroscopy: An alternative probe to the L3,2-edge near-edge structure for the unoccupied densities of d states of 5d metals

We report M3,2-edge x-ray absorption near-edge structure (XANES) measurements for a series of 5d metals, Ta, W, Pt, and Au using a total electron yield technique. It is found that the M3,2 XANES absorption features and their systematics are comparable to their L3,2 counterparts. These results clearly indicate that M3,2-edge XANES can be used as an alternative probe for the unoccupied densities of d states of the 5d metals and their compounds. The implication of these results is discussed.