Synthesis by the polyol process and ionic conductivity of nanostructured La2Mo2O9 powders

Abstract

La2Mo2O9 nanostructured powders were synthesized by the polyol process. The effects of the nature of the polyol, the refluxing time, the hydrolysis ratio, the metal concentration and the addition of hydroxide ions, on the purity and morphology of the powders are determined. Two main morphologies are observed, the particles being in the shape of platelets or spheres, with respectively diethylene glycol or ethylene glycol as solvent. A specific surface area of 24 m2 g-1 was reached by varying the metal concentration. The conductivity measurements were recorded on pellets that present in some cases a closed porosity, the relative density reaching 95% without any milling step. According to the synthesis parameters, the grain conductivity can be slightly increased, the total conductivity remaining only slightly lower than that of pellets made of powders synthesized by solid state reaction.