Molten salts synthesis of double perovskite Sr2-xGdxFeNbO6: Structure, magnetic properties and XPS study

Polycrystalline samples of Sr2-xGdxFeNbO6 with x = 0.0, 0.1, 0.2, and 0.3 were synthesized by the molten salts method. The crystal structure was determined through X-ray diffraction and the corresponding Rietveld analyses. Rietveld refinement and Raman spectroscopy confirmed the tetragonal structure with space group I4/m (No. 87). Magnetization measurements were used to determine the magnetic properties. X-ray photoelectron spectroscopy (XPS) measurements indicate that Sr and Gd orbitals are identified in the structure, which leads to a mixture of oxidation states of Fe to compensate the charge in the compound.