<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Xi Zhang</style></author><author><style face="normal" font="default" size="100%">Yanguang Nie</style></author><author><style face="normal" font="default" size="100%">Weitao Zheng</style></author><author><style face="normal" font="default" size="100%">Jer-Lai Kuo</style></author><author><style face="normal" font="default" size="100%">Chang Q. Sun</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Discriminative generation and hydrogen modulation of the Dirac-Fermi polarons at graphene edges and atomic vacancies</style></title><secondary-title><style face="normal" font="default" size="100%">Carbon</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science/article/pii/S0008622311003393</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">11</style></number><volume><style face="normal" font="default" size="100%">49</style></volume><pages><style face="normal" font="default" size="100%">3615 - 3621</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Using a combination of the bond order–length–strength correlation theory, the spin-polarized tight binding method, the first-principles calculations, and the atomistic photoelectron distillation experiments, we investigated the mechanisms of edge-selective generation and hydrogenated modulation of Dirac-Fermi polarons (DFPs) surrounding the atomic vacancies at a graphite surface and at the edges of graphene nanoribbons (GNR). We found that: (i) the \{DFPs\} with a high-spin density at a zigzag-GNR edge and at an atomic vacancy result from the isolation and polarization of the dangling σ-bond electrons of √3d (d is the C–C bond length) distance along the edge by the locally and densely entrapped bonding electrons; (ii) along an armchair-GNR edge and a reconstructed-zigzag-GNR edge, however, the formation of quasi-triple-bond between the nearest edge atoms of d distance prevents the \{DFPs\} from generation; and (iii) hydrogenation reduces the spin density substantially and turns the asymmetric dumb-bell-like density into the spherical-like pz density. A further C 1s photoelectron spectroscopic purification has confirmed that the generation of the \{DFPs\} is associated with two extra peaks of energy states located at the bottom and the top edge of the C 1s band.&lt;/p&gt;
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