The as-quenched structure of Zr_(80)Pt_(20) melt-spun ribbons containing measured oxygen contents ranging from 184 to 4737 ppm mass was studied. Ribbons containing less than 500 ppm mass oxygen are fully crystallized and consist predominantly of a metastable ordered β-Zr phase with significant solution of Pt. Increasing oxygen content to 1053 and 1547 ppm mass produces a transition to fully amorphous and to mixed amorphous and quasicrystalline structures, respectively. Samples containing 4737 ppm mass consist of quasicrystalline and crystalline phases in an amorphous matrix. The results from this study suggest a critical level of oxygen is required to promote glass formation in Zr_(80)Pt_(20) melt-spun ribbons produced at a specific quench rate.
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