Inhomogeneity and glass-forming ability in the bulk metallic glass Pd42.5 Ni7.5 Cu30 P20 as seen via x-ray spectroscopies

Core-level photoemission spectroscopy and anomalous x-ray scattering (AXS) measurements were performed for the Pd42.5 Ni7.5 Cu30 P20 (PNCP) excellent metallic glass to investigate the chemical nature and local atomic structure, and the results were compared to those in Pd40 Ni40 P20 and Pd40 Cu40 P20. The P2p core levels clearly separate into two states, indicating that the P atoms have two different chemical sites, which is a strong experimental proof for the existence of an elastic inhomogeneity. From the AXS close to the PdK edge, a specific Pd-P-Pd atomic configuration was observed, which is related to the stable state in the P2p core levels. All of the core levels measured in PNCP have the deepest binding energies among these glasses, indicating the most stable electronic states. Local structure around the P atoms is discussed by the AXS data and a metastable crystal appeared in a supercooled metallic alloy close to PNCP.