Boosting the spin polarization and ferromagnetic stability of monolayer C3N through strategic mono-doping and co-doping with copper (Cu) and vanadium (V)

Abstract

The inherently low spin polarization of ferromagnetism in two-dimensional C₃N hinders its application in spintronics. Addressing this, the impact of (V, Cu) co-doping on the spin polarization in monolayer C₃N has been systemically explored through first-principles calculations. The results reveal that doping with a single V or Cu atom at an N site significantly enhances spin polarization compared to doping at a C site. Moreover, substituting a single C or N atom with a V atom results in significantly enhanced spin polarization compared to replacement with a Cu atom. Significantly, V and Cu co-doping at different N sites in C₃N systems uniformly favors ferromagnetic states. A remarkable boost in spin polarization is achieved through strategic co-doping of V and Cu at N sites, separated by a distance of 5.681 Å. This enhancement is attributed to the coupling interactions among the C 2p, N 2p, Cu 3d, and V 3d orbitals. The theoretical investigation suggests an effective route to greatly enhance the spin polarization through targeted 3d transition metal co-doping, contributing to the development of high-performance spintronic devices and advancing quantum computing technologies.