Collective dynamics of liquid potassium studied by inelastic neutron scattering

Новиков, А. Г.; Savostin, V. V.; Shimkevich, Alexander L.; Zaezjev, M.

doi:10.1016/s0921-4526(96)00987-8

Cited by 10 publications

(6 citation statements)

References 11 publications

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“…The first experimental data on liquid potassium appeared surprisingly late relatively to the other liquid metals (Novikov et al, 1996a(Novikov et al, ,b, 1997. Moreover, the kinematic region Q − E spanned in this experiment was quite narrow (10 < Q < 13 nm −1 ) and only partial information on the microscopic dynamics could be obtained.…”

Section: Potassiummentioning

confidence: 86%

Microscopic dynamics in liquid metals: The experimental point of view

2005

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The experimental results relevant for the understanding of the microscopic dynamics in liquid metals are reviewed, with special regards to the ones achieved in the last two decades. Inelastic Neutron Scattering played a major role since the development of neutron facilities in the sixties. The last ten years, however, saw the development of third generation radiation sources, which opened the possibility of performing Inelastic Scattering with X rays, thus disclosing previously unaccessible energy-momentum regions. The purely coherent response of X rays, moreover, combined with the mixed coherent/incoherent response typical of neutron scattering, provides enormous potentialities to disentangle aspects related to the collectivity of motion from the single particle dynamics. If the last twenty years saw major experimental developments, on the theoretical side fresh ideas came up to the side of the most traditional and established theories. Beside the raw experimental results, therefore, we review models and theoretical approaches for the description of microscopic dynamics over different length-scales, from the hydrodynamic region down to the single particle regime, walking the perilous and sometimes uncharted path of the generalized hydrodynamics extension. Approaches peculiar of conductive systems, based on the ionic plasma theory, are also considered, as well as kinetic and mode coupling theory applied to hard sphere systems, which turn out to mimic with remarkable detail the atomic dynamics of liquid metals. Finally, cutting edges issues and open problems, such as the ultimate origin of the anomalous acoustic dispersion or the relevance of transport properties of a conductive systems in ruling the ionic dynamic structure factor are discussed.

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Section: Potassiummentioning

confidence: 86%

Microscopic dynamics in liquid metals: The experimental point of view

2005

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“…and r(q) is a relaxation time, given in l.he approximation of Lovesey [19] Using the 11MSA integral equations presented in section 2.2, we investigated the variation of S(q) with temperature for 5 values of temperature varying from 343K (the melting point of K) and quite close to the 3-10K at which experimental results for dynamic properties are available [11,12] and 75K which was about the lowest temperature at which we could obtain thermodynamic self-consistency (TSC) within our integral equation closure.…”

Section: Integral Equation Theorymentioning

confidence: 99%

“…We Htart by e:omparing our resull.s for the; dispersion e:nrve;s at 343K with the; limited experimental da.t.a give;n in [11,12]. The; resull.s are prese;nteel in Fig.…”

Section: Dynamical Structure Factors S(qo;)mentioning

confidence: 99%

Dynamical structure of undercooled liquid potassium

Akinlade¹,

Ijaduola²

1998

J. Phys.: Condens. Matter

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KJ.al.ic and <]yiia.Tni<:al sl.nid.nrc [Victors for undcrcoolcd PoUisKiinn. T'}i<; KJ.al.ic Nl.rud.im; [Victors c\rc calculaUjd [rorn j.}i<; liybridiz.cd rncan Kp}i<;ri<:al approxirnaLion (HMSA) integral approxirnalioTi UKing pair potcnliais coTiKJ.ni<:l.<;d [rorn a non local pscndopoLential and the dynamical structure factors S(q.u;) within the viscoelastic approximation. We show that the characteristic features of the static structure factors as obtained from Molecular Dynamics simulation are reproduced within the present framework and that essentially, the general features of S(q.u;) at the melting points are still preserved in the undercooled region.

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“…This is well known as de Gennes narrowing [32], which was observed in several liquids [33]. The longitudinal viscosity as a function of Q, the value of 4 3 ηs for the shear viscosity is marked [31]. The solid lines are the MCT calculations using Lee's structure factor [15], and the dotted lines are MCT calculations using Waseda's structure factor [29].…”

mentioning

confidence: 99%

“…Extensive studies of liquid alkali metals have been carried out with inelastic neutron scattering [2][3][4] and inelastic X-ray scattering (IXS) [5][6][7][8][9]. These studies show in general a very low damping of sound modes, which follow a solid-like dispersion and become over-damped only close to the first peak of the structure factor.…”

mentioning

confidence: 99%