Distribution of inequivalent lattice sites in icosahedral quasicrystal Al72.4Pd20.5Mn7.1 studied by NMR

A local spectroscopic study of the distribution of inequivalent lattice sit es in icosahedral Al72.4Pd20.5Mn7.1 single-grain quasicrystal by the Al-27 quadrupole-perturbed NMR is presented. The strongly inhomogeneously broaden ed Al-27 spectra show orientation dependence in the magnetic field that ori ginates from a spatially anisotropic distribution of the electric-field gra dient tensor orientations at inequivalent lattice sites. The results give s pectroscopic evidence that some local atomic arrangements in the quasiperio dic structure are preferred within the manifold of the infinitely many ineq uivalent lattice sites.