Collective dynamics in molten potassium: An inelastic x-ray scattering study

A. Monaco, T. Scopigno, P. Benassi, A. Giugni, G. Monaco, M. Nardone, G. Ruocco, M. Sampoli
2004 Journal of Chemical Physics  
The high frequency collective dynamics of molten potassium has been investigated by inelastic x-ray scattering, disclosing an energy/momentum transfer region unreachable by previous neutron scattering experiments (INS). We find that a two-step relaxation scenario, similar to that found in other liquid metals, applies to liquid potassium. In particular, we show how the sound velocity determined by INS experiments, exceeding the hydrodynamic value by ≈ 30 region 1<Q<3 nm^-1, which marks the
more » ... ure from the isothermal value. We point out how this phenomenology is the consequence of a microscopic relaxation process that, in turn, can be traced back to the presence of "instantaneous" disorder, rather than to the crossover from a liquid to solid-like response.
doi:10.1063/1.1689641 pmid:15267728 fatcat:qmk2a3pcyfc6pbcwim2ul5wt5e