Preparation of calcium plumbate via different route

Abstract

Calcium plumbate Ca2PbO4 was prepared by sol–gel methods (Pechini complex route with two varieties and water soluble polymer method) and by solid state reaction. The sol–gel prepared samples contained calcium plumbate as the only one phase as early as after 2 h annealing at 800 °C. Phase composition was detected by XRD measurement and by Raman spectroscopy. The next annealing at 800 °C for 24 h induced weak Pb losses displayed by present CaO (according to phase equilibrium) and confirmed by XRF measurement. The Pb losses were smaller for the sol–gel prepared samples probably due to earlier formation of Ca2PbO4. Microstructure and grain size were also established. Sol–gel prepared samples had regularly distributed grains with a small distribution interval with median value in order of 1 μm. Differences in microstructure of solid state and sol–gel samples are presented on SEM micrographs.