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Abstract: An exhaustive study of structural, electrical and transport properties on the perovskite stagnate Sn(Ba,Sr)O3 was performed. Samples of SnBa1−x Sr x O3 with 0≤x≤1.00 were prepared by the solid state reaction method. The crystallographic structure was studied by X-ray diffraction experiments and Rietveld refinement using the GSAS code. Results reveal the material synthesized in a cubic structure (space group Pm3̄m, #221) for 0≤x≤0.50 and in an orthorhombic (space group Pnma, #62) for x>0.50. The approximate grain size was found from experiments'' Scanning Electron Microscopy. The electric response was studied by the Impedance Spectroscopy technique from 10.0mHz up to 0,10MHz. Electric polarization measurements for SnSrO3 and SnBaO3 were determined through curves of polarization as a function of applied electric field, which reveal the ferroelectric character of the material. From the saturation polarization the dielectric constants of materials were calculated. [Copyright &y& Elsevier]

We report the production of type perovskite ceramics Sr2FeMnO6, Ba2NdSbO6, Sr2YSbO6 y Ho- Ba2Cu3O7 by means the standard solid state reaction recipe. X-ray diffraction analysis shows that these materials crystallize in complex perovskite with the A2BB'O6 form. [ABSTRACT FROM AUTHOR]

This research paper shows the electrical characterization of tablets type complex perovskite (Sr2FeMnO6, Ba2NdSbO6 and Sr2YSbO6 -semiconductors to room temperature) and HoBa2Cu3O7 (conductor to room temperature but superconductor to 92 K) by means of the Impedance Spectroscopy (IS) technique in solid materials. The measures were carried out in a rank of frequency of 1 mHz to 100 KHz, the experimental assembling was shown, the analysis of the impedance change based on the frequency was also shown, the elements of constant phase that appear in the transmission lines were presented, and the equivalent circuits that can be used to simulate the behavior of the electrical conductivity of these perovskites were also shown. [ABSTRACT FROM AUTHOR]

Abstract: It has been observed that the semiconducting compound SnO2 presents very good results as gas sensor. One important development has been performed to study perovskite oxides for this relevant application. One oxide material which constitutes an excellent candidate for this technological application is BaSnO3. Polycrystalline samples with single phase of BaSnO3 were synthesized by using the solid state reaction method. Samples were characterized structurally by means of X-ray diffraction (XRD) technique. Rietveld refinement, by using the GSAS code, reveals that this material synthesizes in a cubic perovskite, space group Pm3m (#221), with lattice parameter . Electric response was examined through the impedance spectroscopy technique. Results of Bode diagram, from an equivalent circuit, evidence the semiconductor character of material. We carried out a theoretical study by means of the calculation of the bands diagram and the density of states of the BaSnO3. Calculation was performed by employing the density functional theory (DFT), with the generalized gradient approach (GGA). DFT theory permitted to establish that BaSnO3 material has an indirect semiconducting behavior. The calculated gap for this perovskite-like stagnate is at least 0.4eV. Bulk modulus for material was also determined to be 132GPa. [Copyright &y& Elsevier]