Multiferroic vanadium phosphide monolayer with ferromagnetic half-metallicity and topological Dirac states

Ferroelasticity, ferromagnetism, half-metallicity, and topological Dirac states are compelling properties extremely sought in two-dimensional (2D) supplies for superior gadget purposes. Right here, we report first-principles prediction of a dynamically and thermally secure tetragonal vanadium phosphide (t-VP) monolayer that hosts all these fascinating properties. This monolayer is considerably ferromagnetic with polarized spins aligned within the in-plane path through a d-p-d super-exchange coupling mechanism; in the meantime, its tetragonal lattice permits an intrinsic in-plane ferroelasticity with a reversible pressure of 23.7%. In consequence, the ferroelasticity is strongly coupled with ferromagnetism through spin-orbit coupling to allow a deterministic management on the magnetocrystalline anisotropy by an utilized elastic pressure. Extra curiously, this multiferroic t-VP monolayer possesses half-metallicity with an anisotropic, topological Dirac cone residing within the majority-spin channel. We additionally predict a multiferroic t-CrN monolayer, whose ferromagnetism is featured with a excessive Curie temperature of as much as 520 Ok however is weakly coupled to its in-plane ferroelectricity. These outcomes counsel tetragonal 2D lattice as a sturdy atomic-scale scaffold on the idea of which fascinating digital and magnetic properties may be rationally created by appropriate mixture of chemical parts.