Bonding in metal disilicides CaSi2 through NiSi2: Experiment and theory

Synchrotron radiation photoemission experiments with the disilicides of Ti, V, Nb, Cr, Fe, Co, and Ni are combined with self-consistent augmented-spherical-wave calculations of the density of states for metal silicides from Ca-Si to Cu-Si. These results demonstrate the importance of silicon pmetal d bond formation extending to 6 eV below EF for all transition metals. Experiment and theory are combined to show the movement of the nonbonding d states from above EF for Ca-Si to well below EF for Cu-Si. At the same time, the antibonding Si p and Si s states are shown to be relatively insensitive to the particular metal atom in the silicide series. © 1984 The American Physical Society.