Semiconductor-ferromagnetic nature of rare-earth based ferrocobaltite SmFe0.5Co0.5O3

Abstract

Materials in which electronic spin manipulation is possible for the tuning of charge and spin currents are intensively pursued due to the multifunctionality of their potential applications in spintronics technology. In this work, the synthesis and characterization of the crystallographic, optical, electrical and magnetic properties of SmFe0.5Co0.5O3 material is reported. Structural analysis reveals its crystallization in an orthorhombic cell (Pnma space group) with disordered distribution of Fe and Co cations. The optical response evidences the occurrence of a bandgap Eg= 1.0 eV, typical of semiconductor materials, which is corroborated by electrical resistivity measurements and J-E curves, where a varistor-type curve is recorded. Magnetic analysis suggests a predominant antiferromagnetic behavior at low temperatures with weak ferromagnetic response, which strengthens at high temperatures as a result of interactions described by the super-exchange model. Ab-initio calculations of the density of states and electronic band structure predict the semiconductor type response, with an asymmetry of the bandgap between the two spin polarizations, opening channels for tuning polarized spin currents, which is characteristic of ferromagnetic semiconductor type materials.