J. Phys. IV France 7 (1997) C2-1161-C2-1162
Phase Development in Sol-Gel Derived Lead Titanate : A XAS StudyG. Antonioli1, D. Bersani1, P.P. Lottici1, I. Manzini1, S. Bassi1, G. Gnappi2 and A. Montenero2
1 Istituto Nazionale per la Fisica della Materia and Physics Department, University, Viale delle Scienze, 43100 Parma, Italy
2 Chemistry Department and CORIVE, University, Viale delle Scienze, 43100 Parma, Italy
PbTiO3 powders have heen obtained by the sol-gel method using different precursors and catalysts. The whole gelation and crystallisation process was studied by means of XAS spectroscopy at the Ti K-edge and at the Pb Lm-edge. The XANES spectra on the Ti K-edge indicate a marked change of the local environment at 500°C. The local structure around the Ti atoms determined by EXAFS is similar to that ohserved in the pyrochlore phase for annealing temperatures below 500°C . At this temperature both Ti and Pb environments show the occurrence of the Pb-O-Ti bonds indicating the onset of the transformation to the perovskite phase.
© EDP Sciences 1997