Half-metallicity in honeycomb-kagome-lattice Mg3C2 monolayer with carrier doping

TL;DR

This study predicts a stable 2D Mg3C2 monolayer with a honeycomb-kagome lattice that can switch from antiferromagnetic semiconductor to ferromagnetic half-metal through carrier doping, offering potential for spintronic devices.

Contribution

First-principles calculations reveal a new 2D material with tunable magnetic and electronic properties via doping, advancing 2D spintronics research.

Findings

Monolayer Mg3C2 is an AFM semiconductor at ground state.

Carrier doping induces transition to ferromagnetic half-metal.

Half-metallicity originates from specific C orbitals depending on doping type.

Abstract

To obtain high-performance spintronic devices with high integration density, two-dimensional (2D) half-metallic materials are eagerly pursued all along. Here, we propose a stable 2D material with a honeycomb-kagome lattice, i.e., the Mg3C2 monolayer, based on first-principles calculations. This monolayer is an anti-ferromagnetic (AFM) semiconductor at its ground state. We further demonstrate that a transition from AFM semiconductor to ferromagnetic half-metal in this 2D material can be induced by carrier (electron or hole) doping. This magnetic transition can be understood by the Stoner criterion. In addition, the half-metallicity arises from the 2pz orbitals of the carbon (C) atoms for the electron-doped system, but from the C 2px and 2py orbitals for the case of hole doping. Our findings highlight a new promising material with controllable magnetic and electronic properties toward 2D spintronic applications.