Calorimetric Study of Amorphization in Planar, Binary, Multilayer, Thin-Film Diffusion Couples of Ni and Zr

We have utilized differential scanning calorimetry to monitor the solid-state reaction of crystalline metals to form an amorphous alloy in multilayered thin-film diffusion couples of elemental Ni and Zr. The heat of formation of amorphous ${\mathrm{Ni}}_{68}$ ${\mathrm{Zr}}_{32}$ alloy from the elemental metals is measured directly and found to be 35 ± 5 kJ/mole. The kinetics of these reactions has been examined. The activation energy for interdiffusion in the amorphous phase is determined to be $E=1.05\mathrm{}\pm 0.05$ eV.