Higher-order correlation effects on thermodynamic properties of liquid Hg-Na alloys determined by EMF measurements

The electromotive force (EMF) of liquid Hg-Na alloys was measured in detail below 15 at.% Na as functions of Na concentration and of temperature. On the basis of observed EMF values, thermodynamic functions of mixing were obtained at 398 K and 448 K. At 2-8 at.% Na anomalous changes were observed in the concentration dependence curve of the excess partial molar entropy, S_Pi,^E (i=Na or Hg), and on that of the partial molar enthalpy of Na, H_PNa,^E. These anomalies indicate higher-order correlation effects arising from the characteristic changes in the concentration derivatives of n-body (n>or=2) correlation function g_{alpha beta gamma} ⁽ⁿ⁾_{. . .} ( delta g_{alpha beta gamma} ⁽ⁿ⁾_{. . .}/ delta c_i)_{V,T,cj( not=i)}, which could be derived explicitly to be the function of the higher-order (n+1)-body correlation function g_{alpha beta gamma} ^{(n) (n+1)}_{. .} /sub /.