EXPERIMENTAL AND THEORETICAL STUDY OF THE STRUCTURAL, MAGNETIC AND ELECTRONIC PROPERTIES OF THE BA۲GDSBO۶ PEROVSKITE

In this work the procedure to the synthesis of Ba۲GdSbO۶ complex perovskite by the solid-state reaction method is reported. Theoretically a study of the crystalline and electronic structure was performed into the framework of the Density Functional Theory (DFT). The most stable structure is obtained to be a rhombohedral perovskite with a lattice constant a=۶,۰۸۴۰ Å.  Due the occurrence of a mean energy gap of ۲,۸۴ eV close to the Fermi level for both up and down spin polarizations this material is classifies as insulator.  The effective magnetic moment of material obtained from the calculations was ۷,۰ mB. The crystalline structure was analyzed through the X-ray diffraction technique and Rietveld refinement of the experimental data. Results are strongly in agreement with those theoretically predicted. Magnetic response was studied from measurements of magnetic susceptibility as a function of temperature. Results reveal the paramagnetic feature of this material in the temperature regime from ۵۰ K up to ۳۰۰ K. From the fitting with the Curie law the effective magnetic moment was obtained to be ۸,۱ mB, which is slightly higher that the theoretical value for the Gd۳+ isolated cation predicted by the theory of paramagnetism. The energy gap obtained from experiments of diffuse reflectance is relatively in agreement with the theoretical predictions. The dielectric constant as a function of applied frequencies at room temperature was measured. Results reveal a decreasing behavior with a high value of dielectric constant at low applied frequencies

Keywords:

Perovskite material , structure , magnetic feature , electronic properties