An experimental approach to reveal the origin of collective excitations in Ni33Zr67 metallic glass

The dynamical structure factor (S(Q, E)), where E and hQ are the energy and momentum transfer, respectively) of the metallic glass Ni33Zr67 has been measured by neutron inelastic scattering. Previously, we observed dispersive collective excitations in the metallic glass Ni67Zr33. The purpose of this study was to reveal the origin of collective excitations in the Ni33Zr67 glass by a direct comparison with its crystallized counterpart, single-phase poly-crystalline (NiZr2) which is easily obtained by thermal annealing of the glass. Comparisons of S(Q,E) clearly suggest that the collective excitation originates from a combination of three 'optical' modes in the crystalline phase. Crown Copyright (C) 2002 Published by Elsevier Science B.V. All rights reserved.