Half-metallic behavior in rare earth metal (Sm, Gd) co-doped zigzag Gallium Phosphide nanoribbons

Abstract

Using first-principle calculations, we have studied the structural and electronic properties of the Gallium Phosphide (GaP) nanoribbon doped with rare earth (RE) metal elements. The substitution of Ga and P atoms with RE leads to the structural deformation in zigzag GaP nanoribbon. For every nanostructure under study, the binding energy (Eb), density of states (DOS), and electronic band structures have been computed. The bare and pristine undoped GaP show non-magnetic behavior. The bare z-GaPNR shows metallic nature while the pristine z-GaPNR exhibits band gap of 2.44 eV with indirect characteristics. With Samarium (Sm) and Gadolinium (Gd) doping in z-GaPNR, a transformation of the semiconducting nature of z-GaPNRs turns to half metallic one. The transport properties show that half-metal ferromagnetic behavior with 92%–98% spin polarization at the Fermi level is produced by RE (Gd, Sm) co-doped z-GaPNRs. The synergistic effect of the Gd and Sm impurities are seen to diminish energy band gaps. Conversely, we have the energy band gap in spin down energy levels results in semiconducting behavior, whereas in the spin up energy state, metallic behavior is observed. This could be caused by the 4f-states of the Sm and Gd dopants. Therefore, this work presents half-metallic (HM) properties for RE-doped z-GaPNRs. Our study depicts that the electrical, spin, and transport properties of z-GaPNRs could be altered magnificently by co-doping of Gd and Sm rare earth metals. Additionally, the current findings can be used to create a workable method of absolute fermi level shifting for spin energy levels, which is required for applications involving spintronic devices, spin filters, as well as for z-GaPNRs’ electrical characteristics modifications.