Portal de Periódicos da CAPES

Artigo Produção Nacional Revisado por pares

BIBTEX RIS

Synthesis and characterization of CeO2·α-Fe2O3 and CeO2·Pr6O11 ceramic pigments through the solid state reaction and modified sol–gel method

2014; Elsevier BV; Volume: 106; Linguagem: Inglês

10.1016/j.dyepig.2014.02.017

1873-3743

Renata Cristina Olegário, Éder Carlos Ferreira de Souza, José Flávio Marcelino Borges, J.B.M. da Cunha, André Vitor Chaves de Andrade, Sandra Regina Masetto Antunes, Augusto Celso Antunes,

Catalytic Processes in Materials Science

Abstract Ceramic pigments, CeO2·α-Fe2O3 and CeO2·Pr6O11 systems, were synthesized through the solid state reaction at 1300 °C/3 h and modified sol–gel method at 1300 °C/3 h. Pigments presented shades from brown to reddish-orange for the system CeO2·α-Fe2O3, and light-brown to earth-brown for the system CeO2·Pr6O11, and a tendency to the red color in the reflectance spectrum was observed in all pigments. The CeO2·Pr6O11 system, synthesized through both methods, and the CeO2·α-Fe2O3 system, synthesized through modified sol–gel, presented only cerianite phase. The lattice of CeO2·α-Fe2O3 system presents a tendency to expand with the addition of Fe3+ ions, through both methods of synthesis, suggesting an interstitial solid solution formation. The Fe3+ ion solubility limit within the CeO2 lattice is between 2 and 3% in mol. The 57Fe Mossbauer spectroscopy analysis revealed that the sample with 2 and 3 mol% α-Fe2O3, synthesized by the solid state reaction or by the modified sol–gel method presented hematite signals, together with Fe3+ signals within the cerium oxide lattice. For the system CeO2·Pr6O11, changes in the mechanism of solid solution formation depends on the oxidation number of praseodymium reagent.