Hydrothermal synthesis and characterization of Bi2Pb2O7 with pyrochlore structure

Pyrochlore Bi2Pb2O7 was fabricated under low-temperature hydrothermal condi tions and characterized by XRD, IR, SEM DTA-TG, and XPS. XRD analysis shows that the structure of Bi2Pb2O7 is cubic, which is similar to that obtained from high-pressure reactions. XPS measurements suggest that the valences o f Bi and Pb ions are +3 and +4, respectively. The cubic Bi2Pb2O7 is a metas table phase; it decomposes into a new phase with liberation of O-2 at 450 d egrees C. (C) 2000 Academic Press.