Transient ordering states in decagonal Al-Co-Ni at temperatures up to 1000 degrees C
Journal of Alloys and Compounds 342(1-2): 92-95
de Boissieu M
Disordered decagonal quasicrystals with the nominal compositions Al72Ni12Co16 and Al72.5Ni11Co16.5 were investigated by comparative diffuse neutron (N) and X-ray (X) synchrotron studies, respectively, at temperatures up to 1000 degreesC. High resolution X-ray measurements reveal peak splitting consistent with a domain structure of 2D qp and 1D qp lamellae. At higher temperatures the strain fluctuations decrease, giving rise to larger areas of the 2D qp and ID qp domains. In summary, this disordered Al-Co-Ni phase is governed by complex transient ordering states, i.e. twinned lamellar domains of true 2D qc sequences, 1D and periodic domains accompanied by phason straining and phason fluctuations. (C) 2002 Elsevier Science B.V. All rights reserved.