Electric, magnetic and microstructural features of the La2CoFeO6 lanthanide ferrocobaltite obtained by the modified Pechini route

Abstract

In the search for new materials with applicable magnetic properties in spintronic devices, the aim of this work is to report the synthesis of the lanthanide ferrocobaltite La2CoFeO6 using the modified Pechini route; the experimental study of structural, morphological and magnetic properties, and the analysis of the electronic structure and bands are obtained in the framework of the Density Functional Theory. Rietveld refinement of experimental X-ray diffraction patterns revealed the crystallization of this oxide material in a perovskite-like monoclinic structure, space group P21/n (# 14). Scanning electron microscopy and atomic force microscopy images revealed that the surface morphology is essentially polycrystalline, with mean grain sizes between 177 and 188 nm. The dispersive X-ray spectroscopy suggests that the material obtained contains La, Fe, Co and O in the stoichiometric proportions expected by up to 98%. The magnetic susceptibility curves as a function of temperature indicated that the material is ordered ferromagnetically, showing strong irreversibility effects due to the disorder of the Fe and Co cations in the three crystallographic directions of the structure and to the strong distortions in the FeO6 and CoO6 octahedra. Magnetic hysteresis curves confirmed the ferromagnetic character of the material for all temperatures evaluated, up to room temperature. I–V response curves revealed a semiconductor-like behavior with a figure of merit exponent 1.53 of the varistor type. The ferromagnetic semiconductor behavior suggests the potential applicability of the material in spintronic technological devices.

Keywords

• double perovskite
• pechini method
• crystalline structure
• ferromagnetic response
• semiconductor behavior