Structural transformations under annealing of quasicrystalline Mg44Al15Zn41
below 613 K showed that the quasicrystalline constant a(R) was increased b
y about 0.0019 nm. The phase transformation at 613 K from the quasicrystall
ine structure to the 2/1 cubic approximant is reversible and has a topotact
ic character. The 2/1 approximant phase formed during this transformation i
s metastable and decomposes irreversibly above 693 K. (C) 2000 Elsevier Sci
ence S.A. All rights reserved.