2001 Volume 42 Issue 9 Pages 2008-2012
Peak broadening and the peak positions of the Bragg reflections were studied with the high-resolution X-ray diffraction method for the decagonal Al72.7Ni8.5Co18.8 quasicrystal. The full-widths at half-maximum (FWHM) of the Bragg reflections along the longitudinal direction (L), which is perpendicular to the periodic axis, have no Q|| or Q⊥ dependences. On the other hand, notable peak shifts from ideal Bragg peak positions with linear Q⊥ dependence were observed. This means that the Al72.7Ni8.5Co18.8 decagonal phase has linear phason strains. According to the absolute values of the linear phason strains, the transformation from the decagonal phase to an approximant crystal is discussed.