Amorphous alloys synthesized by interface-assisted ion beam mixing in the Ag-W system with the largest positive heat of formation

Amorphous alloys were synthesized by interface-assisted ion beam mixing in the W-rich portion of the Ag-W system. These alloys are characterized by the largest positive heat of formation among the transition-metal alloys and were formed through a two-step structural transition in the alternately deposited Ag-W films. First, during alternate deposition of the nano-sized Ag and W layers, the interfacial free energy drove the Ag-W interaction, which resulted in an intermediate body-centered-cubic (bcc) supersaturated solid solution. Second, the bcc solid solution transformed into an amorphous state upon irradiation at room temperature by 200-keV xenon ions. We report the experimental observations of the Ag-W amorphous alloy formation and a brief discussion concerning the effects of the interfacial free energy and ion irradiation dose on the structural transition observed in the Ag-W films.