Strain-tuned magnetism and half-metal to metal transition in defective BCN monolayer.

Recently, two-dimensional (2D) BCN, an in-plane heterostructure formed by graphene and hexagonal boron nitride, has been successfully synthesized experimentally and exhibits diverse electronic properties. Unfortunately, it has been slow on the application of 2D BCN for spintronics due to the lack of the magnetic ordering. Here, using density functional theory calculations, we explored the effect of vacancy defect and biaxial strain on the electronic and magnetic properties of BCN monolayer. It is demonstrated that BCN monolayer can be converted from nonmagnetic semiconductor to magnetic half-metal/metal by introducing C or B vacancies. The half-metal/metal behavior can be remained under the different vacancy concentrations in defective BCN monolayer. In addition, BCN monolayer with C and B vacancies can be converted between half-metal and metal by applying biaxial strain. Moreover, the magnetic properties of defective BCN monolayer can also be efficiently modulated under the biaxial strain by regulating the spin polarization of the C/N/B 2orbitals. Our findings not only provide an effective way to achieve half-metal/metal transition, but also can induce and manipulate the magnetism of BCN monolayer, which may be utilized for the development of 2D BCN spintronic nanodevices.