UNIDEF 23986
UNIDAD DE INVESTIGACION Y DESARROLLO ESTRATEGICO PARA LA DEFENSA
Unidad Ejecutora - UE
artículos
Título:
Phase transitions of BaTi0.9Rh0.1O3d perovskite-type oxides under reducing environments
Autor/es:
G.C.MONDRAGÓN RODRÍGUEZ; Y. GÖNÜLLÜ; DAVIDE FERRI; ARNIM EYSSLER; EUGENIO H. OTAL
Revista:
MATERIALS RESEARCH BULLETIN
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Año: 2015 vol. 61 p. 130 - 135
ISSN:
0025-5408
Resumen:
Perovskite-type oxides of composition BaTi0.9Rh0.1O3d were prepared following a new chemical route that avoids the formation of hydroxyl species and precipitation, and allows the homogeneous distribution of Rh in the final mixed metal oxide. The high dispersion of Rh and the formation of the solid solution between Rh and the BaTiO3 perovskite is confirmed by means of X-ray diffraction (XRD) and extended X-ray absorption fine structure spectroscopy (EXAFS). The presence of Rh stabilized the hexagonal BaTi0.9Rh0.1O3d phase, which decomposes into barium orthotitanate (BaTi2O4) and metallic Rh in reducing environment. This phase transition starts already at 700 C and is only partially completed at 900 C suggesting that part of the Rh present in the perovskite lattice might not be easily reduced by hydrogen. These aspects and further open questions are discussed.
