▎ 摘　　要

We study the magnetic properties of nanometer-sized graphene structures with of triangular graphene nano-islands using Monte Carlo simulation (MC). The transition temperature of graphene nano-islands formed by two triangular interpenetrating sublattices, Co and Fe, is determined with different values of exchange interactions J(CoCo), J(FeFe), J(FeCo) and different layers for a zero magnetic field and a zero crystal field. The magnetic hysteresis cycles system formed by Co and Fe nano-islands have been established for different values of exchange interactions (J(CoCo), J(FeCo) ), for different values of temperatures and for different sizes of system. The emergence of magnetism in graphene nano-islands with well-defined zigzag edges has been studied using MC with different sizes. These nano-magnets show remanence and hysteresis because of magnetic anisotropy, which originates in the spin-orbit interaction, very small in graphene. These results can provide some guidance to structure design in the nano-islands. The superparamagnetic phase is also obtained in this system at the transition temperature.