PHASON STRAIN IN A MECHANICALLY POLISHED AL-PD-MN ICOSAHEDRAL SINGLE QUASI-CRYSTAL

Two icosahedral Al-Pd-Mn samples extracted from the same Czochralski-g rown single quasicrystal have been studied by high-resolution synchrot ron X-ray diffraction. While the first sample had an almost planar sur face resulting from cleavage, the second had a planar surface obtained by mechanical polishing. In both samples the width of the diffraction peak profiles increases linearly with Q(per), the perpendicular compo nent of the six-dimensional reciprocal lattice vector. However, the br oadening is larger in the polished sample, indicating that phason stra in has been introduced during the polishing process.