The structure of a crystalline approximant (called "PD3c phase") in an Al71.5Co16Ni12.5 alloy annealed at 900°C for 120 h has been studied by high-angle annular detector scanning transmission electron microscopy (HAADF-STEM) and high-resolution transmission electron microscopy (HREM). The PD3c phase has an orthorhombic structure with lattice parameters a = 5.2 nm, b = 0.4 nm and c = 3.7 nm, and the space group of Pmn21 (No. 31). Its structure is characterized as an ordered arrangement of columnar atom clusters with pentagonal symmetry, and can be interpreted as a crystalline approximant related to an ordered decagonal quasicrystal formed by the projection of a NaCl-type hypercubic lattice.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering