NMR and Susceptibility Studies of Al₈₀Mn₂₀ Quasicrystal

Abstract

The temperature dependences of NMR spin-echo spectrum and magnetic susceptibility have been measured in the quasicrystalline phase of Al₈₀Mn₂₀. Compared with the equilibrium crystalline (hexagonal) phase, the susceptibility shows a marked temperature dependence below about 100 K. The widely distributed and temperature dependent NMR spin-echo spectrum has been observed only for the Al sites with a characteristic line shape at low temperatures that we tentatively attributed to a spin-density-wave like random distribution of the local fields at the Al sites. The lack of NMR signal associated with the Mn sites and the temperature dependence of the susceptibility suggest the formation of local magnetic moments on the Mn sites in the quasicrystalline phase.