Tuning electronic structure and magnetic properties of Mn- and Fe-doped arsenene with biaxial strain

Abstract

Effectively controlling and modulating the electronic structure and magnetism is critical for the application of spintronics devices which based on two dimensional (2D) materials. Herein, by using density functional theory (DFT), we investigate synergistic effect of Mn (or Fe) doping and biaxial strain on electronic structure and magnetism of arsenene system. Unstrained Mn-doped arsenene exhibits a half-metallic state, but unstrained Fe-doped structure is narrow and direct band-gap semiconductor. The emerging spin splitting is caused by orbital hybridization of 4p -3d. Therefore, by the Mn and Fe doing, the systems produce a net magnetic moment of 4.00 and 1.00 , respectively. Particularly, the room temperature ferromagnetism (RTFM) can be achieved in two doping structures. Under the condition of coexistence of impurity atom and biaxial strain, for the Mn doping, the systems are still half-metal materials and magnetism remain stable. While the Fe-doped system translates into a magnetic metal state due to the closure of band gap under the tensile strain of 4%. And the magnetic moments have a sudden transition, increase to 3.92, 5.00 and 5.00 under strains of 4%, 6% and 8%, respectively. In addition, the electronic structure and magnetism of Fe doping can also be affected by doping concentration. This work broadens the way about application of arsenene-based spintronic devices.