Pinacca, R.M., Viola, M.C., Pedregosa, J.C., Carbonio, R.E., Lope, M.J. Martínez, and Alonso, J.A.
Abstract: 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 8h, 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−x U0.5+x O3 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 30K. [Copyright &y& Elsevier]