Electrical resistivity of the Na-Pb system: measurements and interpretation

Electrical resistivity measurements for Na-Pb alloys are presented over the whole composition range and in the temperature interval 600-823K. The variations of the electrical resistivity and its temperature dependence with alloy composition exhibit interesting features, i.e. a maximum and a negative minimum respectively, around the composition corresponding to that of Na 4 Pb. The results are discussed in terms of the Faber-Ziman model and the Mott intuitive approach. It is suggested that a tendency towards a metal-nonmetal transition exists which leads to a partial charge transfer from one component of the alloy to the other to form non-metallic species.