Atomic jumps in quasiperiodic Al72.6Ni10.5Co16.9 and relatad crystalline material

Al-27 NMR measurements of the transverse magnetization decay in a decagonal quasicrystal Al72.6Ni10.5Co16.9 detected at temperatures between 300 and 4 K slow, low-activation-energy, diffusive atomic jumps that exhibit properties compatible with the elementary excitations of the quasiperiodic lattices in the form of phason jumps. However, identical atomic motion was observed also in "vacancy-ordered" bcc crystalline Al50Cu35Ni15, indicating that this motion is not quasicrystals specific, but a feature of close-packed atomic structures-either periodic or quasiperiodic-that contain structural vacancies