STUDIES ON THE THERMAL-DECOMPOSITION OF BASIC LEAD(II) CARBONATE BY FOURIER-TRANSFORM RAMAN-SPECTROSCOPY, X-RAY-DIFFRACTION AND THERMAL-ANALYSIS

The thermal decomposition of basic lead(II) carbonate 2PbCO(3) . Pb(OH )(2) in static air under atmospheric conditions has been studied;for t he first time using a combination of thermoanalytical, X-ray diffracti on and Raman spectroscopic techniques. New intermediate compounds of t he type 4PbCO(3) . 3PbO and PbCO3 have been observed in addition to pr eviously reported ones of the type 2PbCO(3) . PbO, PbCO3 . PbO and PbC O3 . 2PbO. Post-decomposition studies have identified the presence of the tetragonal-to-orthorhombic phase transition in PbO. Results are al so presented for the decomposition processes in nitrogen and oxygen at mospheres. Oxidative decomposition studies have shown that Pb3O4 forms in oxygen and in flowing air.