Structure of liquid K-Pb alloys

Abstract

he structure factors of liquid Pb, K0.25Pb0.75, K0.50Pb0.50, K0.65Pb0.35 and K0.80Pb0.20 have been measured by means of neutron diffraction. The main peaks of the structure factors of the alloys are preceded by a pre-peak which is most pronounced in K0.50Pb0.50. This pre-peak indicates that there is considerable ordering in the alloys, although there is also evidence for a tendency towards phase separation in at least one of the alloys. From inspection of the radial distribution functions it follows that Pb clusters are formed, the concentrations of which increase when the equi-atomic composition is approached. A simple model of the structure of K0.50Pb0.50 based on the reference interaction site model proves to be in excellent agreement with the measured structure factor