CONCENTRATION-DEPENDENCE OF THE STRUCTURE OF LIQUID LI-NA ALLOYS

The structural properties of liquid lithium-sodium alloys near the phase separation curve are investigated in the modified hypernetted-chain approximation, by employing the new bridge-function scheme proposed recently by us and the effective interatomic potentials obtained by the pseudopotential theory. The concentration dependence of our results is consistent with the asymmetrical phase separation curve with respect to the concentration. We could also reproduce qualitatively the characteristic features of the concentration-concentration structure factor S(cc)(q) of the 'zero alloy' Li0.61Na0.39 obtained by the neutron diffraction experiment, that is, the divergence of S(cc)(q) in the long-wavelength limit and the ripple around q = 2.2 A-1, and the origin of the latter is clarified.