Structural, chemical bonding, electronic and magnetic properties of KMF₃ (M = Mn, Fe, Co, Ni) compounds

Abstract

KMF₃ (M = Mn, Fe, Co, Ni) compounds crystallize in the cubic perovskite structure with space group Pm3m (#221) at ambient conditions. Structural, chemical bonding, electronic and magnetic properties of these compounds are investigated using the full-potential linearized augmented plane wave (FP-LAPW) method within the density functional theory (DFT). The calculated structural parameters agree well with the experimental measurements. From the elastic properties, it is inferred that these compounds are elastically stable. Moreover, KMnF₃ is found to be ductile in nature while the remaining compounds are brittle. The results of the electronic band structure show that KMnF₃ and KNiF₃ are indirect band gap semiconductors in both spin channels, while KFeF₃ and KCoF₃ are half metallic, being semiconductors with majority spin channel and metals with spin minority channel. The bonding behavior of the studied compounds is expressed as a combination of covalent–ionic behavior. The magnetic study reveals the ferromagnetic behavior for these compounds. The half metallicity and the ferromagnetic behavior favor these compounds for spintronic applications.