Crystalline, Magnetic and Optical Properties of the CaLaSnFeO6 Perovskite

Abstract

In order to obtain new materials with multifunctional properties, CaLaSnFeO₆ samples were synthesized by the solid reaction technique. Structural analysis was performed by X-ray diffraction technique. Rietveld refinement of the experimental data revealed that these materials crystallize in a perovskite-type monoclinic structure (P2₁/n, space group #14) with alternating arrangement of Fe-Sn cations along the three crystallographic axes. The strongly granular character of the surface of the material was observed by scanning electron microscopy micrographs. X-ray energy dispersive spectra exhibited a close correspondence of the composition of the samples with that expected from their stoichiometric formula. Magnetic characterization in the temperature regime 50 K < T < 325 K and applied fields up to 30 kOe suggests the occurrence of a ferromagnetic ordering with Curie temperature T_C = 204 K. Diffuse reflectance spectra revealed the semiconducting characteristic of the CaLaSnFeO₆ double perovskite with a bandgap of E_g = 2.33 eV. To establish the origin of the magnetic interactions, electronic structure calculations were performed in the vicinity of the Fermi level by means of the Density Functional Theory. These properties generate technological expectations in the spintronics industry for the production of information storage devices on magnetic media based on polarized spin currents such as spin valves and magnetic transistors.