Raman spectra and conductivity of PbO–PbCl2–CsCl melts

Abstract

The structure and the conductivity of homogeneous CsCl–PbCl₂–PbO melts with different compositions are studied. The Raman spectra (RS) of the chloride and oxide–chloride melts containing lead oxide have been measured. It is found that the CsCl (71.3 mol %)–PbCl₂ (28.7 mol %) system with the addition of 12 mol % PbO and the CsCl (18.3 mol %)–PbCl₂ (81.7 mol %) system with the addition of 18 mol % PbO contain Pb₃O₂Cl⁺ oxide–chloride groups. The temperature dependences of the electrical conductivity are measured in the PbCl₂–CsCl chloride melts containing 28.7 and 81.7 mol % lead chloride and in homogeneous molten mixtures CsCl (71.3 mol %)–PbCl₂ (28.7 mol %) with the addition of 12 mol % PbO and the CsCl (18.3 mol %)–PbCl₂ (81.7 mol %) with the addition of 18 mol % PbO. Significant degradation of the ion conductive properties of the PbO–PbCl₂–CsCl oxide–chloride melts as compared to those of the PbCl₂–CsCl chloride electrolytes has been revealed. It is shown that the decrease in the electrical conductivity of the PbCl₂–CsCl oxide–chloride melts as lead oxide is added is due to the presence of Pb₃O₂Cl⁺ oxide–chloride groups.