A transmission electron microscopy study of a dislocation dipole and dislocation pairs in an Al₇₀Co₁₅Ni₁₅ decagonal quasicrystal

Abstract

A dislocation dipole in Al₇₀Co₁₅Ni₁₅ decagonal quasicrystal has been observed, for the first time, by means of transmission electron microscopy and compared with dislocation pairs. Diffraction contrast analysis shows that the Burgers vectors of the two dislocations of which the dislocation dipole and the dislocation pairs consist are along the tenfold axis. One can easily differentiate a dislocation pair from a dislocation dipole by using the defocused convergent-beam electron diffraction technique.