Phason strain in a mechanically polished Al-Pd-Mn icosahedral single quasicrystal

Two icosahedral Al-Pd-Mn samples extracted from the same Czochralski-grown single quasicrystal have been studied by high-resolution synchrotron X-ray diffraction. While the first sample had an almost planar surface 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 component of the six-dimensional reciprocal lattice vector. However, the broadening is larger in the polished sample, indicating that phason strain has been introduced during the polishing process.