Thermodynamic, Structural and Transport Properties of Molten Copper-Thallium Alloys

Authors: D. Adhikari, R. P. Koirala, B.P. Singh

Abstract:

A self-association model has been used to understand the concentration dependence of free energy of mixing (GM), heat of mixing (HM), entropy of mixing (SM), activity (a) and microscopic structures, such as concentration fluctuation in long wavelength limit (Scc(0)) and Warren-Cowley short range order parameter ( 1 α )for Cu- Tl molten alloys at 1573K. A comparative study of surface tension of the alloys in the liquid state at that temperature has also been carried out theoretically as function of composition in the light of Butler-s model, Prasad-s model and quasi-chemical approach. Most of the computed thermodynamic properties have been found in agreement with the experimental values. The analysis reveals that the Cu-Tl molten alloys at 1573K represent a segregating system at all concentrations with moderate interaction. Surface tensions computed from different approaches have been found to be comparable to each other showing increment with the composition of copper.

Keywords: Concentration fluctuations, surface tension, thermodynamic properties, Quasi-chemical approximation.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1055104

References:

[1] R.N. Singh and F. Sommer, "Temperature dependence of the thermodynamic functions of strongly interacting liquid alloys", J. Phys. Condens. Matter, vol.4, p. 5345, 1992.
[2] F. Sommer, "Thermodynamic properties of compound-forming liquid alloys", J. Non-Cryst. Solids, vol. 117, pp. 505-512, 1990.
[3] D. Adhikari, "Disorder in liquid Cu-Pd alloy", Phase Transitions, vol. 84, pp. 308-314, 2011.
[4] K. Hoshino, "On the temperature dependence of the structure factor of the liquid Li-Pb alloy",J. Phys. F: Met. Phys. , vol. 13, p. L189, 1983.
[5] W.H. Young, "Structural and thermodynamic properties of NFE liquid metals and binary alloys" ,Rep. Prog. Phys. Vol. 55, p. 1769, 1992.
[6] P.J. Flory, "Thermodynamics of high polymer solutions", J. Chem. Phys. Vol. 10 , pp. 51-61, 1942.
[7] D. Adhikari, I.S. Jha, and B.P. Singh, "Structural asymmetry in liquid Fe-Si alloys", Philos. Mag., vol.90, pp. 2687-2694, 2010.
[8] A.B. Bhatia and R.N. Singh, "A quasi-lattice theory compound forming molten alloys", Phys. Chem. Liq. Vol. 13, pp. 177-190, 1984.
[9] R. Singh and F. Sommer, "Segregation and immiscibility in liquid binary alloys", Rep.Prog. Phys., vol. 60, pp.57-150, 1997.
[10] L.C. Prasad, R.N. Singh, and G.P. Singh, "The role of size effects on surface properties", Physics and Chemistry of Liquids, vol. 27, pp. 179- 185, 1994.
[11] R. Hultgren, P. D. Desai, D.T. Hawkins, M. Gleiser, and K.K. Kelley, Selected values of the thermodynamic properties of binary alloys, ASM, Metal Park, OH, 1973.
[12] B.E. Warren, X-ray Diffraction, Addison-Wesley, Reading, MA, 1969.
[13] J.M. Cowley, "An Appropriate Theory of Order in Alloys", Phys. Rev., Vol. 77, pp.669, 1950.
[14] L. S. Darken, R.W. Gurry, Physical chemistry of metals, McGraw Hill. New York, ,p.53, 1953.
[15] R.N Singh and F. Sommer, "Thermodynamic Investigations of Viscosity and Diffusion of binary Molten alloys", Phys. Chem. Liq. Vol. 36, p. 17, 1998.
[16] R. Novakovic, "Thermodynamics, surface properties and microscopic functions of liquid Al-Nb and Nb-Ti alloys". Journal of Non-Crystalline Solids, vol. 356, pp. 1593-1598, 2010.
[17] B.C. Anusionwu and C.A. Madu, "Theoretical studies of mutual diffusivities and surface properties of Cd-Ga liquid alloys-, PRAMANAJ. Physics, vol.72, pp. 951-967, 2009.
[18] H.M. Lu and Q. Jiang"Surface Tension and Its Temperature Coefficient for Liquid Metals" J. Phys. Chem. B , vol. 109, pp. 15463-15468, 2005.
[19] J. A.V. Butler, "The thermodynamics of the surface of solutions" Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, vol.135, pp. 348- 375, 1932.
[20] R. Novakovic, " Thermodynamics, surface properties and microscopic functions of liquid Al-Nb and Nb-Tl alloys", J. Non-Crystalline Solids, vol. 356, pp. 1593-1598, 2010.
[21] N.H March and J.A. Alonso,"Non-monotonic behaviour with concentration of the surface tension of certain binary liquid alloys", Phys. Chem. Liq. vol. 46, pp.522-526, 2008.