Growth induced phason strains in icosahedral quasicrystals of Al-Li-Cu.

Growth induced phason strains have been examined by x-ray diffraction in icosahedral quasicrystals of Al-Li-Cu produced by various growth techniques. We find that the amplitudes of phason strains are about 7 times larger in the melt-spun ribbons as compared with the Bridgman grown icosahedral crystals and increase logarithmically with growth velocity. The lineshapes vary systematically reflecting the growth induced microstructures. In contrast, the peak broadening and thus the correlation lengths of disorder ~1000angstroms are very similar for all samples regardless of the growth conditions.