Functionalization of boron phosphide monolayers for spintronic applications by doping with alkali and alkaline earth metals

Abstract

In this work, new d0 magnetic materials are developed by doping boron phosphide (BP) monolayer with alkali (Li, Na, and K) and alkaline earth (Be, Mg, and Ca) metals. First-principles calculations confirm good dynamical and thermal stability of pristine monolayer. This two-dimensional (2D) is intrinsically non-magnetic semiconductor with band gap of 0.90/1.36 eV as calculated by PBE/HSE06 functional. B-P chemical bond is predominantly covalent generated by the electronic hybridization with small portion of ionic character formed by the charge transfer from B atom to P atom. Doping with Li, Be, and Mg at B sublattice preserves the non-magnetic nature, causing either considerable reduction of band gap or metallization. Meanwhile, the monolayer is significantly magnetized with total magnetic moment between 0.94 and 3.86 µBin the remaining cases. Herein, magnetic properties are produced mainly by p orbital of impurities and their neighbor host atoms, while Ca-3d orbital contributes also to the magnetism of Ca-doped systems. Moreover, the doping process conducts to the emergence of either half-metallic or magnetic semiconductor in BP monolayer to get prospective d0 magnetic materials to generate spin current. Results presented herein demonstrate the effectiveness of doping with alkali and alkaline earth metals to get magnetizing BP monolayer with feature-rich electronic properties, such that the doped systems can be recommended for applications in nano spintronic devices.