8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Fri 911:10-14:00P1.9Fingerprints of order and disorder in the microscopicdynamics of liquid metalsValentina Giordano 1 and Giulio Monaco 21 LPMCN, CNRS et Université Lyon 1, 43 bd du 11 Novembre 1918, 69622, Villeurbanne,France2 ESRF, Grenoble, FranceIt is largely accepted that liquids are characterized by a short range order usually correspondingto that of the solid phase at the same density. It is less clear to what extent dynamic properties ofliquids and crystals can be compared. We report here on the investigation of the high frequencydynamics of a prototype simple liquid, sodium and an anisotropic complex liquid, gallium. Wepresent a quantitative comparison of the collective excitations in liquid and polycrystalline Na,which reveals a striking close correspondence between the two phases, allowing for the identificationof the very specific fingerprint of short range order and overall structural disorder on themicroscopic dynamics of the liquid. We will show that the same quasi-crystalline approach to thedata analysis in the case of liquid Ga allows for the discrimination of the short range order of thisatypical liquid.9