Abstract
The aim of this work was to propose the experimental partial isothermal section of the Al-Pd-Co phase diagram at 1035 °C and to study the structure of quasicrystalline approximant ε_n. Scanning electron microscopy including energy dispersive X-ray spectroscopy, X-ray diffraction and scanning transmission electron microscopy were used in the investigation. Calculation of atomic structures was performed using Monte Carlo simulation minimising Empirical Oscillating Pair Potentials energy. Besides the proposed partial isothermal section at 1035 °C, homogeneity ranges of phases ε_n, U, F, V,δ, and W were schematically projected. Various modifications of ε_n were observed and/or identified in the investigated alloys. The structures of ε_(22) and ε_(34) were experimentally observed in the Al-Pd-Co system for the first time. Furthermore, their atomic structure models were created. Last but not least, it was experimentally documented that the regular arrangement of tiles in ε_n structures can be interrupted by structural defects. The obtained results form a comprehensive picture of the individual structural modifications of the ε_n phase.
NSTL
Elsevier