NOTE ON THE BURGERS VECTOR DETERMINATION OF DISLOCATIONS IN 2-DIMENSIONAL QUASI-CRYSTALS

Dislocations in quasicrystals can be observed by conventional diffract ion contrast transmission electron microscopy. Within the framework of kinematical theory, the extinction conditions for dislocations are de rived in the case of two-dimensional quasicrystals. Analogously to the case of icosahedral quasicrystals, one also expects the existence of a so-called weak-extinction condition, that is the dislocation can be in and out of contrast for collinear vectors. The theory is presented in detail for the case of decagonal quasicrystals and the experimental results are discussed.