Crystalline structure, magnetic response and electronic properties of RE2MgTiO6 (RE = Dy, Gd) double perovskites

The synthesis, crystal structure, morphology, magnetic properties and electronic calculations of two members of the family of double perovskite materials RE2MgTiO6 (RE = Dy, Gd) are described. X-ray powder diffraction measurements show that these materials crystallize in monoclinic perovskite structures with space group P2(1)/n (#14). Unit cell parameters, atomic positions, tilt angle, inter-atomic distances and site occupancies were calculated by Rietveld through the GSAS code reveal. Lattice parameters for Dy2MgTiO6 were a = 5.3624(4) angstrom, b = 5.5973(2) angstrom and c = 7.6794(2) angstrom, and for Gd2MgTiO6 a = 5.3143(5) angstrom, b = 5.5826(2) angstrom and c = 7.6324(2) angstrom. Samples morphology analyzed by scanning electron microscopy reveal strongly coupled grains with mean size 3 mu m. Paramagnetic behavior is evidenced by magnetic susceptibility measurements and Curie-Weiss fitting supplies effective magnetic moments which lay 98% in agreement with the theoretical predictions for the isolated rare earth elements for each compound. (C) 2014 Elsevier B.V. All rights reserved.