Room temperature d 0 ferromagnetism in carbon doped LaH3: insights from density functional theory simulations

Abstract

Abstract Employing the state-of-the-art density functional theory with both generalized gradient approximation and the hybrid HSE06 functional, along with the incorporation of spin–orbit coupling, we have engineered stable room temperature ferromagnetism (FM) (RTF) in nonmagnetic LaH3 through C substitution at octahedral and tetrahedral H sites where the induced magnetic moment is mostly contributed by the 2p orbital of the C atom. It is interesting that the magnetic signature is switched on with an impurity concentration as low as 1.04 at% with a magnetic moment of ∼1.0 µ B per impurity, where the localized behavior of the 2p states of C, along with significant exchange splitting energy, can be attributed as the origin of the induced magnetic moment. The verification of the Stoner criterion in the material further confirmed the onset of FM in the system, and the computed Curie temperature is found to be well above room temperature. Reduced formation energy and the requirement of lower impurity concentration ensure practical feasibility towards a spintronic device where RTF is established from the nonmagnetic host and the dopant.