Microsc. Microanal. Microstruct. 4, 341-346 (1993)
DOI: 10.1051/mmm:0199300402-3034100

Electron-beam irradiation effects in Al-Ni-Co decagonal quasicrystal

K. Edagawa, K. Suzuki, M. Ichihara et S. Takeuchi

Institute for Solid State Physics, The University of Tokyo, Roppongi, Minato-ku, Tokyo 106, Japan

Abstract
By observing the change of the diffraction pattern and the lattice image, structural changes by electron beam irradiation have been investigated for Al-Ni-Co ordered decagonal quasicrystal, which was recently identified by the present authors. By 100 kV electron beam irradiation, essentially no change was detected in the diffraction pattern even after half an hour exposure to the electron beam. On the other hand, by 300 kV irradiation, drastic changes were observed after only a few minutes of irradiation; in the diffraction pattern the diffraction spots became diffuse and all the ordered spots and weak main spots disappeared; in the lattice image, the characteristic ring contrast in the decagonal phase became indistinct. However, no reconstruction of the ring pattern was recognized, suggesting that the phason strains, if introduced, are limited to components of wavelength shorter than the inter-ring distances (˜ 2 nm).

PACS
6180F - Electron and positron radiation effects.

Key words
Electron beam effects -- Electron irradiation -- Electron diffraction -- Lattice structure -- Quasicrystals -- Ternary alloys -- Aluminium base alloys -- Nickel alloys -- Cobalt alloys -- Al70Ni17Co13 -- Al Co Ni


© EDP Sciences 1993