Determination of the tiling type and phason strain analysis of decagonal quasicrystals in Al-Ni-Co alloys

From high-resolution electron micrographs of the decagonal phases of the Al 72.5Co11Ni16.5 and Al70Co15Ni15 alloys, tilings are produced by connecting prominent structural features. Indexing the tiling vertices as the projecti on of a five-dimensional periodic lattice and investigation of the distribu tion of the vertices in orthogonal space gives information about the tiling model and possible phason strains. The technique also reveals domain bound aries which separate regions differing only in the amounts of linear phason strain.