Dislocations in decagonal Al70Ni15Co15 and Al73Ni10Co17 were studied by means of diffraction-contrast imaging and de-focused convergent beam electron diffraction in a transmission electron microscope. In addition to dislocations with Burgers vectors parallel to the periodic and quasi-periodic directions, a type of dislocation was found which had a Burgers vector with components in both the periodic and quasi-periodic directions. The parallel-space component of this Burgers vector had a length of 2.5Å. The quasi-periodic Burgers vectors were found to have parallel-space lengths of 2.9 and 4.7Å. The Burgers vectors were correlated with interatomic vectors of the decagonal structures. Dislocation reactions were identified by determining the Burgers vectors of dislocations in triple-node arrangements. A model was proposed, for the dislocation reactions, which was in accord with the results of microstructural studies.

Dislocations and Dislocation Reactions in Decagonal Al-Ni-Co Quasicrystals. P.Schall, M.Feuerbacher, K.Urban: Physical Review B, 2004, 69[13], 134105 (10pp)