TY - JOUR
T1 - Observation of magnetic edge state in graphene nanoribbons
AU - Joly, V. L.Joseph
AU - Kiguchi, Manabu
AU - Hao, Si Jia
AU - Takai, Kazuyuki
AU - Enoki, Toshiaki
AU - Sumii, Ryohei
AU - Amemiya, Kenta
AU - Muramatsu, Hiroyuki
AU - Hayashi, Takuya
AU - Kim, Yoong Ahm
AU - Endo, Morinobu
AU - Campos-Delgado, Jessica
AU - López-Urías, Florentino
AU - Botello-Méndez, Andrés
AU - Terrones, Humberto
AU - Terrones, Mauricio
AU - Dresselhaus, Mildred S.
PY - 2010/6/22
Y1 - 2010/6/22
N2 - The electronic structure and spin magnetism for few-layer-graphene nanoribbons synthesized by chemical vapor deposition have been investigated using near-edge x-ray absorption fine structure (NEXAFS) and electron-spin resonance (ESR). For the pristine sample, a prepeak was observed below the π* peak close to the Fermi level in NEXAFS, indicating the presence of additional electronic states close to the Fermi level. The intensity of this prepeak decreased with increasing annealing temperature and disappeared after annealing above 1500°C. The ESR spectra, which proved the presence of localized spins, tracked the annealing-temperature-dependent behavior of the prepeak with fidelity. The NEXAFS and ESR results jointly confirm the existence of a magnetic edge state that originates from open nanographene edges. The disappearance of the edge state after annealing at higher temperatures is explained by the decrease in the population of open edges owing to loop formation of adjacent graphene edges.
AB - The electronic structure and spin magnetism for few-layer-graphene nanoribbons synthesized by chemical vapor deposition have been investigated using near-edge x-ray absorption fine structure (NEXAFS) and electron-spin resonance (ESR). For the pristine sample, a prepeak was observed below the π* peak close to the Fermi level in NEXAFS, indicating the presence of additional electronic states close to the Fermi level. The intensity of this prepeak decreased with increasing annealing temperature and disappeared after annealing above 1500°C. The ESR spectra, which proved the presence of localized spins, tracked the annealing-temperature-dependent behavior of the prepeak with fidelity. The NEXAFS and ESR results jointly confirm the existence of a magnetic edge state that originates from open nanographene edges. The disappearance of the edge state after annealing at higher temperatures is explained by the decrease in the population of open edges owing to loop formation of adjacent graphene edges.
UR - http://www.scopus.com/inward/record.url?scp=77956323477&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.81.245428
DO - 10.1103/PhysRevB.81.245428
M3 - Article
AN - SCOPUS:77956323477
SN - 1098-0121
VL - 81
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 24
M1 - 245428
ER -