Soft X-ray emission study of Pd-Ni-Cu-P bulk metallic glass

Soft X-ray emission spectra were measured on Pd_42.5Ni_7.5Cu₃₀P₂₀ and Pd₄₀Ni₄₀P₂₀ bulk metallic glasses near the Ni and Cu 2p_3/2 absorption edges to evaluate, respectively, the Ni and Cu 3d partial density of states (DOS) in the valence band. The Pd 4d, and the Ni and Cu 3d partials in the conduction-band were also obtained from X-ray absorption spectra around the Pd 3p_3/2, Ni, and Cu 2p_3/2 absorption edges, respectively. The partial DOS of each d state was estimated from the spectra, and the feature of the electronic structure in these glasses were discussed in detail. In particular, it was found that the Pd 4d partial DOS near the Fermi energy largely decreases and becomes localized by replacing the Ni atoms with the Cu atoms, which may closely related to the excellent glass-forming ability in the Pd_42.5Ni_7.5Cu₃₀P₂₀ bulk metallic glass.