Structural and Raman Vibrational Studies of CeO2-Bi2O3 Oxide System

الملخص EN

A series of ceramics samples belonging to the CeO2-Bi2O3 phase system have been prepared via a coprecipitation route.

The crystallized phases were obtained by heating the solid precursors at 600∘C for 6 hours, then quenching the samples.

X-ray diffraction analyses show that for x<0.20 a solid solution Ce1−xBixO2−x/2 with fluorine structure is formed.

For x ranging between 0.25 and 0.7, a tetragonal β′ phase coexisting with the FCC solid solution is observed.

For x ranging between 0.8 and 0.9, a new tetragonal β phase appears.

The β′ phase is postulated to be a superstructure of the β phase.

Finally, close to x=1, the classical monoclinic α Bi2O3 structure is observed.

Raman spectroscopy confirms the existence of the phase changes as x varies between 0 and 1.