Artículos de revistas
Structural evolution of the double perovskites Sr2B'UO6 (B' = Mn, Fe, Co, Ni, Zn) upon reduction: Magnetic behavior of the uranium cations
Fecha
2011-11Registro en:
Pinacca, Ruben Miguel; Viola, Maria del Carmen; Pedregosa, Jose Carmelo; Carbonio, Raul Ernesto; Martínez Lope, M. J.; et al.; Structural evolution of the double perovskites Sr2B'UO6 (B' = Mn, Fe, Co, Ni, Zn) upon reduction: Magnetic behavior of the uranium cations; Pergamon-Elsevier Science Ltd; Materials Research Bulletin; 46; 11; 11-2011; 1755-1760
0025-5408
CONICET Digital
CONICET
Autor
Pinacca, Ruben Miguel
Viola, Maria del Carmen
Pedregosa, Jose Carmelo
Carbonio, Raul Ernesto
Martínez Lope, M. J.
Alonso, J. A.
Resumen
We describe the preparation of five perovskite oxides obtained upon reduction of Sr2B′UO6 (B′ = Mn, Fe, Co, Ni, Zn) with H2/N2 (5%/95%) at 900 °C during 8 h, and their structural characterization by X-ray powder diffraction (XRPD). During the reduction process there is a partial segregation of the elemental metal when B′ = Co, Ni, Fe, and the corresponding B′O oxide when B′ = Mn, Zn. Whereas the parent, oxygen stoichiometric double perovskites Sr2B′UO6 are long-range ordered concerning B′ and U cations. The crystal structures of the reduced phases, SrB′0.5−xU0.5+xO3 with 0.37 < x < 0.27, correspond to simple, disordered perovskites; they are orthorhombic, space group Pnma (No. 62), with a full cationic disorder at the B site. Magnetic measurements performed on the phase with B′ = Zn, indicate uncompensated antiferromagnetic ordering of the U5+/U4+ sublattice below 30 K.