Electronic structures and magnetic properties of Zn- and Cd-doped AlN nanosheets: A first-principles study

In this paper, the magnetic properties, electronic structures and the stabilities of Zn/Cd incorporated two-dimensional AlN nanosheets are investigated by the first-principles method. Numerical results indicate that Zn and Cd substituting Al atom in AlN nanosheets introduce some holes into the 2p orbitals of the N atoms, and the holes mainly come from spin-down 2p orbitals of the N atoms. The magnetic moment of 1.0 μ_B is produced by Zn/Cd doping AlN nanosheets, and the main component of the magnetic moment of the system is contributed by the partially filled 2p states of the N atoms around the dopant. In particular, when Zn/Cd substituting Al atoms, the magnetic coupling is found to be ferromagnetic. We attribute the hole-mediated p-d interaction to the created ferromagnetic coupling. More importantly, the result of formation energy indicates that Al atom is more inclined to be replaced by Zn atom rather than Cd. This finding is beneficial to developing the spin electronic devices.