Change in local atomic structure during formation of the icosahedral quasicrystalline phase in Zr₇₀Pd₃₀ glassy alloy

The local atomic structures in glassy, supercooled liquid and quasicrystalline phases for a Zr₇₀Pd₃₀ binary alloy have been examined by the x-ray diffraction method. It was found that the local atomic structure in the glassy phase can be identified as the distorted icosahedral-like structure around Zr and remains almost unchanged by the phase transformation into the supercooled liquid. In the formation process of the icosahedral phase, approximately one Zr atom substitutes with one Pd atom in this local structure. This kind of atomic rearrangement may improve the perfectibility of the as-quenched icosahedral-like cluster, leading to the phase evolution of the icosahedral phase.