Magnetic properties of nanographites at low temperature

Both orbital diamagnetic and Pauli paramagnetic contributions to the magnet ic response in ribbon-shaped nanographite systems with zigzag and armchair edges an discussed. These systems possess edge states, strongly localized n ear zigzag edges. The edge states lead to a sharp peak in the density of st ates at the Fermi level and generate a Pauli spin susceptibility with a nea rly Curie-like temperature dependence, In nanographite systems this paramag netic contribution of the edge states can compete with the diamagnetic orbi tal magnetic signal of the bulk. At high temperature the system is diamagne tic and at low temperature the paramagnetic behavior dominates. (C) 2000 El sevier Science B.V. All rights reserved.