X-ray photoelectron spectroscopy analysis of bulk Pd-Ni-P metallic glasses

The core-level and valence-band spectra were obtained from high-resolution X-ray photoelectron spectroscopy of the bulk glassy and crystalline PdxNi80-xP20 (x = 20–70) alloys. Upon crystallization of glassy Pd40Ni40P20, which exhibits the highest glass stability, a small change in chemical bonding is observed. This appears as a charge transfer from P atoms to Ni and Pd atoms. The level of chemical bonding between P and the metals seems to increase linearly as a function of x throughout the composition range. The density D(EF) of states at the Fermi level is significantly lower for the alloys with respect to those of the d-band metals, in agreement with the Nagel-Tauc criterion for glass stability. However, its value is not the lowest for the x = 40 composition which is most resistant to crystallization. The existing electronic models are not fully adequate for explaining the high glass stability of the Pd40Ni40P20 alloy. © 1999 Taylor & Francis Group, LLC.