JCPT  Vol.7 No.3 , July 2017
First-Eutectic Features of Polar Metals in Double Systems
Abstract: It is known that the dense part of any liquid metal consists of ramified clusters of almost regular tetrahedrons (triangular pyramids with atoms in their vertexes) that are connected into chains by faces. Any metal additive as a second component of liquid alloy can be both beyond these clusters as separated atoms and into them as inherent clusters. The liquid-metal alloy transfers into the second state, at the first eutectic of the solvent. This polymorphic transition of liquid matrix is discovered in the systems, Pb-K and Na-Pb, by molecular-dynamic simulating their microstructure and in experiments on scattering slow neutrons by these alloys of different compositions. In the first system, the obtained results identify both the homogeneous alloy at low concentrations of potassium in liquid lead and the alloy clustering, (Pb4K)n, at potassium concentrations following the eutectic, Pb0.91K0.09. In the second one at the concentrations of lead more than 2%, just the second state is discovered with the clusters, (Na4Pb)n. One can expect the same polymorphic transition in the eutectic, Na0.93Tl0.07, with the micro-inhomogeneity, (Na6Tl)n, and with the melting point of 64 C. This eutectic maintained by the oxygen-free technology and enriched by the isotope, 205Tl, can become the best coolant for fast nuclear reactors due to the depressed chemical activity of sodium and composition stability.
Cite this paper: Shimkevich, A. and Shimkevich, I. (2017) First-Eutectic Features of Polar Metals in Double Systems. Journal of Crystallization Process and Technology, 7, 55-63. doi: 10.4236/jcpt.2017.73004.

[1]   Van der Lugt, W. (1991) Zintl Ions as Structural Units in Liquid Alloys. Physica Scripta, 39, 372.

[2]   Reijers, H.T.J. and van der Lugt, W. (1990) Molecular-Dynamics Study of Liquid NaPb, KPb, RbPb, and CsPb Alloys. Physical Review B, 42, 3395-3405.

[3]   Subbotin, V.I., Arnoldov, M.N., Kozlov, F.A. and Shimkevich, A.L. (2002) Liquid-Metal Coolants for Nuclear Power. Atomic Energy, 92, 29-40.

[4]   Alekseev, P.N. and Shimkevich, A.L. (2016) Efficacy of Eutectic Modification of Liquid-Metal Coolants. Atomic Energy, 119, 218-219.

[5]   Blagoveshchenskii, N.M., Morozov, V.A., Novikov, A.G., Savostin, V.V., Shimkevich, A.L and Shimkevich, I.Y. (2005) Microscopic Structure of Liquid Lead-Potassium Alloys: Neutron-Diffraction and Molecular Dynamics Investigation. Physica B: Condensed Matter, 364, 255-262.

[6]   Kolokol, A.S., Shimkevich, А.L. and Shimkevich, I.Y. (2008) On Composition Converting Liquid Metal Alloys. Journal of Physics: Conference Series, 98, Article ID: 042021.

[7]   Shimkevich, A.L. (2008) The Composition Principles for Designing Nuclear-Reactor Materials. N.N. PonomarevStepnoi Edition, IzdAt, Moscow. (In Russ)

[8]   Shimkevich, I.Y. and Shimkevich, A.L. (2014) MD Simulated Microstructure of Liquid Sodium Alloyed with Lead. Materials Sciences and Applications, 5, 556-567.

[9]   Grube, G. and Schmidt, A. (1936) The Na-Tl Phase Diagram. Zeitschrift für Elektrochemie, 42, 201-209.

[10]   Shimkevich, A.L. and Shimkevich, I.Y. (2011) Molecular Dynamics Simulation of the Clustering of Minor Lead Additives in Liquid Sodium. Journal of Metallurgy, 2011, Article ID: 890321.

[11]   Kolokol, A.S. and Shimkevich, A.L. (2010) Topological Structure of Density Fluctuations in Condensed Matter. Journal of Non-Crystalline Solids, 356, 220-223.

[12]   Ivanovsky, M.N., Morozov, V.A., Ponomarev-Stepnoi, N.N. and Shimkevich, A.L. (1988) Component First-Order Phase Transition. Soviet Atomic Energy, 65, 878-881.

[13]   Shimkevich, A.L. (1999) The Fluctuation Theory of Impurity Micro-Heterogeneity of Liquid-Metal Coolants. Proceedings of the High School. Nuclear Power, No. 3, 6-16.

[14]   Lamprecht, G.J., Dicks, L. and Crowther, P. (1968) Solubility of Metals in Liquid Sodium. II. The System Sodium-Lead. The Journal of Physical Chemistry, 72, 1439-1441.

[15]   Kikoin, I.K., Ed. (1976) Tables of Physical Constants. Atomizdat, Moscow.

[16]   Meijer, J.A., Geertsma, W. and Van der Lugt, W. (1985) Electrical Resistivities of Liquid Alkali-Lead and Alkali-Indium Alloys. Journal of Physics F: Metal Physics, 15, 899-910.

[17]   Alekseev, P.N., Shimkevich, A.L. and Shimkevich, I.Y. (2015) Eutectic Na-Tl and Pb-Mg Alloys as Liquid-Metal Coolants for Fast Nuclear Reactors. In: Brebbia, C., Ed., Computational Methods and Experimental Measurements XVII, WIT Press, Southampton, 343-353.