d0 magnetism and large magnetoelectric effect in BC4N nanoribbons

Magnetism and magnetoelectric effect of armchair BC4N nanoribbons are explored from density functional theory. 100% spin polarization presents in the N-rich nanoribbons due to sigma-dangling bond states induced by the unpaired N atoms. In the nanoribbons with “paired” B and N atoms, however, striking magnetism is also found to survive, rationalized by a unique zigzag-like pairing pattern. The ribbons can present remarkable edge magnetoelectric effects, for which the edge magnetoelectric coefficient is defined and calculated. The obtained d0 magnetism and the large magnetoelectric effect are helpful to explore possible spintronic applications in BCN systems.