Thermodynamic study of liquid lithium–lead alloys using the EMF method

Liquid Li–Pb alloys were investigated by the electromotive force (emf) method at Li concentrations of 0.025⩽XLi⩽0.965 mole fraction and at temperatures from 775 to 975 K. The experiments were conducted at constant temperature, and the Li concentration was changed by the coulometric-titration technique. The two-phase Li–Bi alloys and liquid lithium were used as the reference electrodes. The dependence of emfs on temperature for each investigated alloy was linear, and from the linear equations (E=a+bT), partial Li excess Gibbs energies, partial enthalpies and entropies of lithium were calculated, and compared with previously published data. The excess stability function ES and the concentration–concentration partial structure factor Scc(0) were calculated and discussed in relation to the neutron diffraction data and other properties. A change in the type of chemical bonding near the composition Li4Pb is indicated. This study was initiated since Pb–17Li eutectic alloy has been proposed as a breeder blanket fluid for fusion reactors.