Magnetism and magnetic transport properties of the polycrystalline graphene nanoribbon heterojunctions

Magnetic transport properties of the polycrystalline graphene nanoribbons with a zigzag-armchair-zigzag structure are investigated systematically. It shows that grain boundaries (GBs) can induce significant localized electron states and magnetic ordering in the region consisting of GBs and armchair segment, and the interdomain electronic transmission across the GBs is transparent or blocked completely depending on the spin direction (α or β) of electrons and GB type (A or B), which causes a special spin polarization for the magnetic transport. Especially, the perfect spin-filtering, spin-rectifying, and giant magnetoresistance effects can be realized simultaneously in such heterojunctions.276