Formation of icosahedral quasicrystalline phase in Zr₇₀Ni₁₀M₂₀(M=Pd,Au,Pt) ternary metallic glasses

An icosahedral quasicrystalline phase was confirmed as a primary precipitation phase in melt-spun Zr₇₀Ni₁₀M₂₀ (M = Pd, Au and Pt) ternary metallic glasses with two-stage crystallization process. The onset temperature of the transformation from amorphous to icosahedral phase are 687 K for Pd, 754 K for Au and 783 K for Pt at a heating rate of 0.67 K s^-1. The size of the icosahedral particles is in the range of 5-20 nm. The second crystallization reaction results in the formation of Zr₂Ni+Zr₂Pd and Zr₂Ni+ZrPt phases in the Zr-Ni-Pd and Zr-Ni-Pt alloys, respectively, and Zr₃Au phase in the Zr-Ni-Au alloy through a single exothermic reaction. The formation of nanoscale icosahedral phase indicates the possibility that icosahedral short-range order exists in the glassy state.