Structural characterization of decagonal quasicrystals in non-equilibrium Al-Ni-Co alloys
In this paper,the atomic resolved HAADF-STEM imaging technique and SAED were used to characterize the structure of decagonal quasicrystals in non-equilibrium Al-Ni-Co alloys.The result showed that the basic structural unit was composed of a five-fold symmetry atomic cluster in an equilibrium Al-Ni-Co decagonal superstructure variant and a unique symmetry-breaking atomic cluster in a non-equilibrium Al-Ni-Co decagonal quasicrystal.This decagonal quasicrystal presented a new Al-Ni-Co superstructure variant.The existence of the symmetry-broken atomic cluster in the quench cooling state led to the generation of phase defects,which destroyed the long-range order of the quasicrystal.There was no obvious difference in the distribution of Amman lines and the characteristic phason distribution in the observation region,reflecting that the linear phason strain of the quasicrystal phase in this region was homogeneous,completely different from the structure characteristics of the decagonal quasicrystal phase in the equilibrium state.
万方数据
维普
