Effect of the synthesis conditions on the crystal, local, and electronic structure of Ce1-x3+ Cex4+ AlO3 + x/2

Resumo

Cerium monoaluminate Ce_1-x³⁺ Ce_x⁴⁺ AlO_3+x/2 powders with low contents of Ce⁴⁺ cations (х ~ 0.052) were synthesized. A set of modern local structure sensitive methods of analysis, including X-ray absorption spectroscopy and Raman spectroscopy, were used to study the crystal, local, and electronic structures of the synthesized compounds. The degree of reduction and the thermal stability to oxidation of reduced powders depend not only on the reduction conditions but also on the conditions of heat pretreatment of the initial samples. It was concluded that the reaction 4CeAlO₃ + O₂ ↔ 4CeO₂ + 2Al₂O₃ is reversible.