Study of lanthanide based Ln₂MgSe₄ (Ln = Er, Pm) spinels for spintronic and optoelectronic applications

Abstract Herein, the full potential linearized augmented plane wave (FP-LAPW) method within the framework of density functional theory (DFT) is used to examine the physical features of Ln 2 MgSe 4 (Ln = Er, Pm) spinel selenides. Exchange correlation energies are estimated through modified Becke–Johnson potential (mBJ). Band structures (BS) and density of states (DOS) data proved that Er 2 MgSe 4 is ferromagnetic (FM) semiconductor while Pm 2 MgSe 4 is half metallic (HFM) ferromagnetic in nature. The Er- f contributed majorly to the vicinity of Fermi level for both compounds. The structural stability is determined through calculating the tolerance factor and geometry optimization, while thermodynamical stability has been realized by computing the formation enthalpy. Furthermore, various optical parameters have been computed which describe the considered materials’ response to incident light. Our study explored the physical properties of two Ln based spinels which are found to have potential for being used in various optoelectronic and spintronic devices.