Crystalline, Magnetic and Electronic Structure of the Ba$_{2}$DySbO$_{6}$ Complex Perovskite

Abstract

In this work, we report the synthesis of the Ba$_{2}$DySbO$_{6}$ new double perovskite by means of the solid-state reaction recipe from high-purity oxide powders of BaCO$_{3}$, Dy$_{2}$O$_{3}$, and Sb$_{2}$O$_{5}$. The analysis of the crystal structure was carried out through the X-ray diffraction technique with posterior Rietveld refinement of the experimental diffraction data by the GSAS code. Results reveal that the Ba$_{2}$DySbO$_{6}$ material crystallizes in a rhombohedral perovskite structure, belonging to the R-3 (#148) space group with lattice parameter a = 5.96260(5) Å, and angle $\alpha$ = 60.008$^{\circ }$. The magnetic characterization was performed by measurements of magnetic susceptibility as a function of temperature. The behavior observed in the temperature regime from 4 K up to 300 K was paramagnetic. The characteristic magnetic parameters were obtained from the fitting with the Curie equation, obtaining the values of susceptibility independent of temperature 0.00633 emu/mol and effective magnetic moment 8.9 $\upmu _\mathrm{{B}}$, which is 84 % in agreement with the expected value predicted by the Hund’s rules. The electronic structure was calculated by means of linearized augmented plane waves in the framework of the density functional theory (DFT). This study considers the cohesion energies as a function of the lattice parameter, with a lattice constant a, whose value is 98 % in agreement with the experimental result. Curves of density of states as a function of the wave number reveal that this material behaves as an insulator with energy gap 3.65 eV. This result was corroborated by diffuse reflectance experiments adjusted to the Kubelka–Munk equation. The effective magnetic moment obtained from the DFT calculations was $7.7\,\upmu _\mathrm{{B}}$.