Atomic motions in the crystalline Al50Cu35Ni15 alloy

This paper describes quasi-elastic neutron scattering experiments on the Al 50Cu35Ni15 alloy Dcl-formed on the IRIS spectrometer at ISIS, Rutherford Ap pleton Laboratory, and on the MIBEMOL spectrometer at Laboratoire Leon Bril louin, Saclay. The aim was to investigate if atomic hopping motions are res tricted only to occur in systems with quasicrystalline local order. It is f ound that frequent jumps of Cu and Ni atoms between different interstitial lattice positions on the time scale 1 to 100 ps are taking place in this al loy at high temperature. This is the same time scale that has been found ea rlier in quasicrystals and it suggests that this kind of motion is likely t o take place in any metallic alloy at high temperature and that it is not a special property of quasicrystals.