L2,3absorption edges inNi2Si

We report an energy-loss investigation around the $\mathrm{Ni} L_{2,3}$ edge in ${\mathrm{Ni}}_2$Si in order to study the empty density of states above $E_F$. The comparison with Ni shows in ${\mathrm{Ni}}_2$Si a reduction and broadening of the "white line," a small edge shift toward higher energies, and an $L_3-L_2$ branching ratio closer to the statistical value. The near-edge features within the single-particle approximation are ascribed to the $d$ part of the empty antibonding $p-d$ hybridized states. The absorption structures were compared with the available results of bremsstrahlung isochromat spectroscopy. Differences were found and ascribed to selection-rule effects.