Nearly flat bands and ferromagnetism in the terminated Mn2C MXene

• Published in: Computational Condensed Matter 2023-06, Vol.35, p.e00806, Article e00806
• Main Authors: Kozak, Victoria V., Fedorova, Natalja A., Olshevskaya, Julia S., Kovaleva, Alena V., Shubin, Alexander A., Tarasov, Anton S., Varnakov, Sergey N., Ovchinnikov, Sergei G., Tomilin, Felix N., Avramov, Pavel V.
• Format: Article
• Language: English
• Subjects: 2D magnetism; B3LYP; Ferromagnet; Half metal; Hydroxylated/oxygenated/halogenated MXene; MXene; Nanomaterials; Spintronics
• ISSN: 2352-2143; 2352-2143
• DOI: 10.1016/j.cocom.2023.e00806

Using Density Functional Theory and Periodic Boundary Conditions it is shown that the hydroxylated/oxygenated/halogenated Mn2C monolayer is a 2D ferromagnetic material with a local Mn ions magnetic moment of 2.7μв per unit cell. Upon oxygenation the ferromagnetic coupling between Mn ions can be transformed into a superposition of magnetic states. In particular, the intrinsic magnetic moments in the hydroxylated/halogenated Mn2C monolayer can attain up to 6μB per unit cell. It is found that oxygen termination induces flat bands in the band structure, which evidence for the strong electron correlations and could lead to the implementation of exotic quantum phases in 2D crystals and high-temperature superconductivity. Along with the potential of the hydroxylated Mn2C monolayer characterized by the half-metallicity for application in spintronic devices as a perfect spin injector/detector, this material like other conventional MXenes is promising for the use in energy storage, electromagnetic interference shielding, and sensing. [Display omitted] •Hydroxylated/oxygenated/halogenated Mn2C monolayers are a 2D ferromagnetic materials.•Mn2C surface passivation by F and Cl ions yields the maximum magnetic moments up to 5.63 μB.•Hydroxylated Mn2C monolayer characterized by 100% spin polarization.