Amorphous iron zirconium formed by solid state reaction

We report on the first iron based amorphous alloy formed by the process of solid state reaction. Amorphous iron zirconium was observed to result from thermal anneals of layered crystalline elemental constituents. Starting material was electron beam evaporated with about 50 monolayers of each constituent per layer, which results in an average composition of Fe61Zr39 and a compositional wavelength of 22 nm. Thermal anneals at 623 K were performed in vacuum, and x-ray diffraction was used to determine the structure. A calculated metastable free energy diagram shows the reaction is driven by a large thermodynamic driving force (several kcal/mole).