Structure and dynamics of the liquid 3d transition metals near melting. An ab initio study

Abstract

The static and dynamic properties of several bulk liquid 3d transition metals at thermodynamic conditions near their respective melting points have been evaluated by using ab-initio molecular dynamics simulations. The calculated static structure factors, show an asymmetric second peak followed by a more or less marked shoulder which points to a sizeable amount of icosahedral local order. Special attention is devoted to the analysis of the longitudinal and transverse current spectral functions and the corresponding dispersion of collective excitations. For some metals, we have found the existence of two branches of transverse collective excitations in the second pseudo-Brillouin zone. Finally, results are also reported for several transport coefficients.

An ab initio study of the static, dynamic and electronic properties of some liquid 5d transition metals near melting

“…However, for the other 5𝑑 metals we observe that the associated 𝑍 (𝜔) displays one peak along with a (higher-frequency) shoulder/peak and the corresponding transverse dispersion shows two branches. We note that a similar correspondence was found in AIMD simulation studies of several liquid 3𝑑 and 4𝑑 transition metals [30][31][32]. In principle, such a connection should not be unexpected because several years ago used the MC theory to formulate a theory of the VACF based on contributions arising from the coupling of the single particle motion to the collective longitudinal and transverse currents.…”

“…By using the present AIMD results for the diffusion coefficients and the viscosities of the liquid 5𝑑 metals we have analyzed the accuracy of the SE relation. The results are plotted in figure 16, along with similar AIMD-based data for the liquid 3𝑑 and 4𝑑 metals [30][31][32] In the last few years, another topic of interest has been the appearance of small, weak shoulders in the dynamic structure factor of liquid metals at wavevectors in the wavevector region around 𝑞 𝑝 /2 and the frequency region between the quasielastic and inleastic peaks. These features were first noticed in an IXS measurement of the 𝑆(𝑞, 𝜔) of l-Ga near melting [60] and were corroborated by an OF-AIMD simulation study.…”

“…The number of equilibrium configurations listed in table 1 were those used for the evaluation of the static, dynamic and electronic properties of the corresponding liquid metal. We notice that this same simulation method has already proved its capability to deliver an accurate description of several static, dynamic and transport properties of other bulk liquid metals [23][24][25][26][27][28][29][30][31][32].…”

First principles determination of some static and dynamic properties of the liquid 3d transition metals near melting

“…This paper presents recent ab initio molecular dynamics simulation studies for a range of bulk static, dynamic and electronic properties of the liquid 3d transition metals at thermodynamic conditions near melting. We review some of our previous calculations [1][2][3][4][5] along with several new results.…”

“…In our recent studies of the liquid 3d transition metals [1][2][3][4][5], we were interested in the calculation and analysis of their dynamic properties. Besides its intrinsic interest, we were also motivated by the recent finding of some remarkable features such as low-energy transverse-like excitations in the dynamic structure factor and/or the appearance of a high-frequency branch in the transverse current dispersion relation, in addition to the usual one that appears at low frequencies.…”