Decagonal quasicrystals of Al70Ni10+xFe20-x(0 ≤ x ≤ 10) were investigated by convergent-beam electron diffraction (CBED) and transmission electron microscopy (TEM). It was revealed by the CBED method that the alloys with 0 ≤ x ≤ 7 belong to the space group of the noncentrosymmetric P10m2 and those with 7 < x ≤ 10 to the centrosymmetric P10/mmm. High resolution electron microscope images detected the existence of a specific pentagonal atom cluster in all the alloys investigated. Dark-field microscopy disclosed that the change in space group at x ≈ 7.5 takes place upon the sudden decrease of the domain size or the rapid mixing of the atom clusters with the positive and negative polarities.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry