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Phonon-like and single particle dynamics in liquid lithium

T. Scopigno·U. Balucani·A. Cunsolo·C. Masciovecchio·G. Ruocco·F. Sette·R. Verbeni
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Abstract

The dynamic structure factor, S(Q,E), of liquid lithium (T=475 K) has been determined by inelastic x-ray scattering (IXS) in the momentum transfer region (Q = 1.4-110 nm-1). These data allow to observe how, in a simple liquid, a phonon-like collective mode evolves towards the single particle dynamics. As a function of Q, one finds: i) at low Q's, a sound mode with a positive dispersion of the sound velocity, ii) at intermediate Q's, excitations whose energy oscillates similarly to phonons in the crystal Brillouin zones, and iii) at high Q's, the S(Q,E) approaches a Gaussian shape, indicating that the single particle dynamics has been reached.

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T. Scopigno, U. Balucani, A. Cunsolo, C. Masciovecchio, G. Ruocco, F. Sette, R. Verbeni. 1999-11-02. Phonon-like and single particle dynamics in liquid lithium. https://doi.org/10.1209/epl%2Fi2000-00253-5

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