STEM Structural Investigation of RE-Au-Si 1/1 Approximants

RE-Au-Si (RE=Ho, Tb) systems are 1/1 Tsai-type quasicrystalline approximants with a cluster center decoration that can vary from a disordered tetrahedron to a rare-earth atom. The local atomic structure of three different samples was observed by scanning transmission electron microscopy and interpreted in the light of high-angle annular dark field simulated scanning transmission electron microscopy images. It is found that the combination of these two methods allows to identify differences in the chemical decoration of the cluster centers through quantitative analysis of line profiles. image