Transition-metal embedded carbon nitride monolayers: high-temperature ferromagnetism and half-metallicity

High-temperature ferromagnetic materials with planar surfaces are promising candidates for spintronics applications. Using state-of-the-art density functional theory (DFT) calculations, transition metal (TM = Cr, Mn, and Fe) incorporated graphitic carbon nitride (TM@gt-C₃N₄) systems are investigated as possible spintronics devices. Interestingly, ferromagnetism and half-metallicity were observed in all of the TM@gt-C₃N₄ systems. We find that Cr@gt-C₃N₄ is a nearly half-metallic ferromagnetic material with a Curie temperature of ~450 K. The calculated Curie temperature is noticeably higher than other planar 2D materials studied to date. Furthermore, it has a steel-like mechanical stability and also possesses remarkable dynamic and thermal (500 K) stability. The calculated magnetic anisotropy energy (MAE) in Cr@gt-C₃N₄ is as high as 137.26 μeV per Cr. Thereby, such material with a high Curie temperature can be operated at high temperatures for spintronics devices.High-temperature ferromagnetic materials with planar surfaces are promising candidates for spintronics applications. Using state-of-the-art density functional theory (DFT) calculations, transition metal (TM = Cr, Mn, and Fe) incorporated graphitic carbon nitride (TM@gt-C₃N₄) systems are investigated as possible spintronics devices. Interestingly, ferromagnetism and half-metallicity were observed in all of the TM@gt-C₃N₄ systems. We find that Cr@gt-C₃N₄ is a nearly half-metallic ferromagnetic material with a Curie temperature of ~450 K. The calculated Curie temperature is noticeably higher than other planar 2D materials studied to date. Furthermore, it has a steel-like mechanical stability and also possesses remarkable dynamic and thermal (500 K) stability. The calculated magnetic anisotropy energy (MAE) in Cr@gt-C₃N₄ is as high as 137.26 μeV per Cr. Thereby, such material with a high Curie temperature can be operated at high temperatures for spintronics devices.

Electronic supplementary information (ESI) available: Computational details, optimized structures, phonon band structures, phonon DOS, MD simulations, RMSD plots at three different temperatures (300 K, 500 K and 1000 K), spin-polarized TDOS, PDOS, Bader charges, mechanical properties (Young's modulus and Poisson ratio), total electron densities and electrostatic potentials (ESP) plots, energy diagram of d-orbital splitting, magnetic properties calculation details and references. See DOI: 10.1039/c6nr03282f