Test of the universal scaling law for square well liquid metals

Abstract

A universal scaling law relating the dimensionless diffusion coefficient with excess entropy of a liquid [M. Dzugutov, Nature (London), 381 (1996), 137] is tested for liquid noble metals due to their fundamental importance both in society and industry. The square well form of interatomic potential is used to study liquid noble metals because it possesses the basic nature of real liquids. The radial distribution function (RDF), g(r) and self diffusion coefficient, D of liquid noble metals were derived using statistical mechanical square well (SW) model under random phase approximation, which was proposed by Rao and Murthy [R. V. Gopala Rao and A. K. Murthy, Physics Letters A, 51 (1975), 3]. g(r) and D data of liquid noble metals were employed to compute excess entropy, SE using scaling law, surface entropy, SV through temperature derivative of D under linear trajectory principle and microscopic reducing parameter; Enskog collision frequency, Γ. Further new equations have been derived from equation of state (EOS) for the SW potential and verified them to compute structure factor in the long wavelength limit. The results obtained were compared with available experimental results and we find there is fair agreement between theoretical and experimental values. Present study shows the applicability of the Dzugutov scaling law for square well liquids.