Cationic distribution in the new Nd2CaSnO6 perovskite type phase

The new Nd2CaSnO6 double perovskite oxide has been synthesized in polycrystalline form by a conventional solid-state reactions process at 1300°C in air atmosphere. Structure refinement, realized by Rietveld analysis using the X-ray powder diffraction (XRD) data, shows that the compound crystallizes in monoclinic symmetry with P21/n space group and Z = 2. Obtained unit-cell parameters are: a = 5.6585(1) Å, b = 5.9254(1) Å, c = 8.1883(2) Å, = 90.116(1) ° and V = 274.5(1) Å3 . The cationic distribution over the A- and B-sites of this perovskite structure can be illustrated by the [Nd1.90Ca0.10]A[Nd0.10Ca0.90]B’[Sn1.00]B’’O6 crystallographic formula. The monoclinic structural distortion involves long-range ordering between Sn4+ (in 2c site) and a random mixture (0.90Ca2+; 0.10Nd3+) (in 2d site) all at the B-perovskite sites.