DENSITY OF VIBRATIONAL-STATES IN HIGHLY DISORDERED-SYSTEMS THROUGH RAMAN-SCATTERING AND ATOMIC-SCALE SIMULATION

Raman scattering is used as a probe with regard to the understanding o f local structural arrangements and correlated lattice dynamics in hig hly disordered systems. This investigation is shown to be particularly fruitful if one records the signal over a very wide frequency range ( including Stokes, anti-Stokes and multiple-order processes). Results o n amorphous semiconductors and vitreous materials are discussed in com parison with those obtained by other techniques (inelastic neutron sca ttering) or numeric simulations (valence-force-held or molecular dynam ics approaches). It is shown that the dynamic response of a disordered material is essentially accounted for by simply considering the latti ce dynamics of its crystalline counterpart.