TEMPERATURE-DEPENDENCE OF THE GENERALIZED VIBRATIONAL DENSITY-OF-STATES OF AL70CO15NI15 AND AL62CO15CU20SI3

The temperature dependence of the atomic dynamics of AlCoNi and AlCoCu Si was investigated via the generalized vibrational density of states (GVDOS) using neutron inelastic scattering. With increasing temperatur e we observe a strong anharmonic softening of the dynamics which is es sentially linear with temperature for AlCoNi but shows a step for AlCo CuSi. From the shape of the GVDOS we conclude that in AlCoNi the short range order changes little with temperature while it does change in A lCoCuSi. In the case of AlCoNi the GVDOS measured at 296 K can be near ly quantitatively described by a computer simulation based on a tiling model and ab initio pair potentials for Al and Co. (C) 1997 Elsevier Science S.A.