Valence electronic structures of crystalline compounds and glassy alloys of Ni silicides, Pd silicides, and Ni borides are studied by soft-x-ray spectroscopy over wide ranges of Si and B concentrations. The samples prepared include bulk compounds, glassy ribbons, and amorphous sputtered films. Silicon Kβ emissions of Ni and Pd silicides generally consist of a prominent peak fixed at ≊4.5 and ≊5.8 eV below the Fermi level $E_F$, respectively, with a shoulder near $E_F$ which grows and shifts toward lower energy with increasing Si concentration. The former is identified as due to Si p–like states forming Si 3p–Ni 3d or Si 3p–Pd 4d bonding states while the latter as due to the corresponding antibonding states. Ni $L_3$ and Pd $L_3$ emissions of these silicides indicate that Ni 3d and Pd 4d states lie between the above two states. These local electronic configurations are consistent with partial-density-of-states (PDOS) calculations performed by Bisi and Calandra. Similar electronic configurations are suggested for Ni borides from B Kα and Ni $L_3$ emissions. Differences of emission spectra between compounds and glasses of similar compositions are rather small, but some enhancement of the contribution of antibonding states to the PDOS near $E_F$ is suggested for certain glasses over that of the corresponding compounds. These features are discussed in connection with the compound stability and glass formability.

• Received 19 February 1985

DOI:https://doi.org/10.1103/PhysRevB.32.6853