화학공학소재연구정보센터
Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, Vol.340, 7-12, 2000
Magnetic and transport properties of nanographites
Magnetic and transport properties of nanographites are investigated in graphite ribbons with zigzag and armchair edges. One of the most remarkable features of these systems is the appearance of edge states, strongly localized states near zigzag edges. Because the edge states lead to a sharp peak of density of states at the Fermi level, the graphite ribbons with zigzag edges show Curie-like temperature dependence of the Pauli paramagnetic susceptibility. This paramagnetic contribution competes with the orbital diamagnetism, leading to a crossover from high-temperature diamagnetic behavior to low-temperature paramagnetic behavior in nanographite ribbons with zigzag edges. The edge states are also responsible for the low-energy electronic transport properties. Here we study the junctions connecting nanographite ribbons of different width by the Landauer approach. The conductance as a function of the chemical potential shows rich structure and a large number of dips of zero conductance. The perfect reflectivity originates from the formation of standing wave resonances in the junction region.