CORRELATION BETWEEN THE STRUCTURAL DEFECTS INDUCED BY BALL-MILLING OFPB3O4 AND THE STRUCTURE OF PBO YIELDED FROM ITS THERMAL-DECOMPOSITION

The influence of grinding in a high planetary ball-mill on the texture and thermal stability of Pb3O4 has been studied. The results obtained show that the crystallite size decreases while the level of microstra ins increases upon increasing the grinding time. The Pb3O4-->PbO conve rsion temperature decreases by increasing the grinding time of the pre cursor when the orthorhombic phase of PbO (massicot) becomes stabilize d with regards to the tetragonal modification (litharge). The analysis of the X-ray diffraction profiles of the lead monoxide obtained from the thermal decomposition of Pb3O4 demonstrates that PbO keeps memory of the lattice imperfections of Pb3O4. Moreover, higher the grinding t ime of Pb3O4, higher the reactivity of the resulting PbO sample toward s reoxidation.