M. Abdalla

Synthesis and Characterization of Sm1-xZrxFe1-yMgyO3 (x, y = 0.5, 0.7, 0.9) as Possible Electrolytes for SOFCs

The novel perovskite oxide series of Sm1-xZrxFe1-yMgyO3 (x,y = 0.5, 0.7, 0.9) were synthesized by solid state reaction method. X-ray diffraction (XRD), Rietveld refinement, scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and conductivity analysis were carried out. XRD patterns of sintered materials revealed the shifted Bragg reflection to higher angle for the higher content of Zr and Mg. This is related to the ionic size of the dopant elements. Rietveld refinement showed that all compounds crystallized in cubic space group of Fm-3m. SEM images showed that the grains were well defined with highly dense surfaces makes it potential as an electrolyte material in solid oxide fuel cells (SOFCs) or gases sensors. Impedance spectroscopy at 550-800 °C shows that conductivity is higher at higher temperature. Sm0.5Zr0.5Fe0.5Mg0.5O3 shows the highest conductivity of 5.451 × 10-3 S cm-1 at 800 °C. It was observed that 50% molar ratio of Mg and Zr doping performed highest conductivity.

Synthesis, Structural and Thermal Properties of Layered Perovskites SmBaMn 2 O 5+d for SOFCs Applications

New layered perovskite oxides with samarium (Sm+3) rare earth doped layered perovskite materials were synthesized and characterised by using X-ray diffraction, scanning electron microscopy (SEM), particle size measurements and thermogravimetric analysis (TGA). Sm0.5Ba0.5MnO3-δ and SmBMn2O5+δ, were synthesized by conventional solid state reaction method. Rietveld analysis of XRD data shows that all materials crystallize in the orthorhombic symmetry in the Pmmm space group. SEM images show porous structures which should be suitable as electrode materials for solid oxide fuel cells (SOFCs). TGA results indicate the mass loss of 0.022% for SmBMn2O5+δ. Density calculation shows the materials have about 85% relative density.

Synthesis and characterization of Sm0.5Ba0.5MnO3-δ as anode materials for solid oxide fuel cells

The material performance is a crucial issue in the current fuel cell technology, and for this reason we present this new series of Samarium family which can be used as electrode giving a high performance in a particular application. Sm0.5Ba0.5MnO3-δ was prepared by solid state reaction method and characterized by using X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Rietveld analysis of XRD data shows that the material has an Orthorhombic crystal structure with cell parameter a = 3.883(1) A b = 3.8742(5) A c = 7. 762(4) A, in the Pmmm space group. TGA analyses shows that the materials is going to decrease by 0.32%. The density of the materials was calculated from structural refinement and found to be 8.372 gm/cm3.