New, so-called, N -phase revealed around ~Al 79 Fe 12 Pt 9 (B. Grushko, J. Alloys Comp. 829 (2020) 154444) has been studied by 3D electron diffraction and high-angle annular dark-field imaging. Its structure is concluded to be monoclinic with the cell parameters of a ≈ 1.243 nm, b ≈ 1.654 nm, c ≈ 1.97 nm and β ≈ 107.24°. The symmetry of the unit cell can be described by either P 2 1 (No. 4) or P 2 1 / m (No. 11) space groups. Despite extensive study, the structure solution of the N -phase was impeded by abundant structural defects . Electron diffraction data point to a close structural relation between the Al–Fe–Pt N -phase and the E-phases earlier observed in the Al–Ru–Rh or Al–Co–Rh(Ir) alloy systems. Both the N -phase and E-phases have very similar values of the b and c cell parameters while their cell parameters a are related as a N ≈ a E /2sin(2π/5). The monoclinic Al–Fe–Pt N phase is established as a distinct member of the pseudo-decagonal intermetallic family. • Al 79 Fe 12 Pt 9 N -phase is P2 1 /m with a≈1.243, b≈1.654, c≈1.97 nm and β≈107.24°. • Electron diffraction shows multiple structural defects. • Tiling reveals pentagon-based decagonal motifs related to known phases. • Structural comparison shows close relation of N phase to the E and ε 6 . • Presence of minor ε 6 and ξ phases was detected and relations were suggested.
Tamir et al. (Fri,) studied this question.