2D antiferromagnetic semiconducting FeCN with interesting properties

Abstract

Two-dimensional magnetic materials have demonstrated favorable properties (e.g., large spin polarization and net magnetization) for the development of next-generation spintronic devices. The discovery of such materials and insight into their magnetic coupling mechanism has become a research focus. Here, on the basis of first-principles structural search calculations, we have identified a fresh FeCN monolayer consisting of edge-sharing Fe triangle sublattices and FeC₃N₂ rings, which integrates antiferromagnetism, semiconductivity, and planarity. Interestingly, it possesses a large magnetic anisotropy energy (MAE) of 614 μeV per Fe atom, a narrow band gap (E_g) of 0.47 eV, a large magnetic moment of 3.15 μ_B, and a proper Néel temperature (T_N) of 97 K. The direct exchange between the nearest-neighbor Fe atoms in the triangle sublattice is mainly responsible for the AFM ordering. Its high structural stability, stemming from the collective contribution of covalent C–C and C–N bonds, ionic Fe–N bonds, and metallic Fe–Fe bonds, provides a strong feasibility for experimental synthesis.