A theoretical simulation of the magnetic properties of nanocomposites based on graphene nanoflakes

Using exact diagonalization, the density matrix renormalization group approach and the quantum Monte-Carlo method, we studied the peculiarities of the magnetization profiles and the possibility of spin switching for the Heisenberg spin models of low-dimensional composite magnets formed by graphene nanoclusters and complex transition-metal compounds. For these models, we found the presence of intermediate plateaus in the low-temperature magnetization profiles, which is in agreement with known experimental and theoretical studies of the magnetization profiles of nanostructured magnets with the ferrimagnetic spin ordering in the ground state. For spin-chain model of composite magnets proposed, we also found a possibility of single and double spin switching with the macroscopic jump of the ground state spin results from frustrated spin interactions.