Quasicrystals and nano-quasicrystals in annealed ZrAlNiCuAg metallic glasses

Quasicrystals and nano-quasicrystals are observed in annealed Zr65Al7.5Ni10Cu12.5Ag5 and Zr65Al7.5Ni10Cu7.5Ag10 metallic glasses. Through systematic transmission electron microscopy (TEM) analyses, selected area electron diffraction (SAED) and nano-beam electron diffraction (NBED) patterns corresponding to five-, three- and twofold rotational symmetry are obtained, demonstrating that the precipitated phases in the first stage devitrification of the alloys are icosahedral quasicrystalline phases. The discovery of the quasicrystals directly reflects the intrinsic relationship between the Zr-based bulk metallic glasses and the icosahedral structure.