Electron spin resonance in graphite

Matsubara, Keiko; Tsuzuku, Takuro; Sugihara, Kō

doi:10.1103/physrevb.44.11845

Cited by 45 publications

(40 citation statements)

References 12 publications

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“…Earlier reports of ESR studies on graphite revealed a dependence of the g-factor on temperature as well as the external magnetic field orientation relative to the (out of plane) c-axis [34,35]. These studies indicate that when B ⊥ c-axis, g ⊥ is essentially constant with respect to temperature and very close to that of the free electron, with g ⊥ = 2.0023.…”

mentioning

confidence: 71%

Probing Electron Spin Resonance in Monolayer Graphene

et al. 2017

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mentioning

confidence: 71%

Probing Electron Spin Resonance in Monolayer Graphene

et al. 2017

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“…Determination of the g-factor value from EPR measurements was first attempted by Wagoner [13] in the 1960's and recently was the subject of the studies of the Matsubara et al [15]. Then, Blinowski et al [16] analyzed electron structure of graphite and in particular the Dyson shape of EPR line related to a high conductivity of bulk graphite samples.…”

Section: Discussion Of the G-factor Valuementioning

confidence: 99%

Valence state of paramagnetic centers in fullerenes

et al. 1994

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Charge distribution on individual carbon atoms of a fullerene molecule C n depends on the number of atoms it comprises, n. Only C60 has the same charge on all its carbon atoms while other molecules containing from n = 32 to n = 84 molecules are characterized by a variety of charge distributions. A neutral C60 molecule is diamagnetic and does not show EPR signal. Charged C60 v molecules, where vis the valence taking values from v = -6 to v = +1, show EPR signals for odd v and for v = 2 when a fullerene molecule is in the triple state. EPR lines of isolated fullerene ions are narrow in the whole temperature range whereas EPR lines of MexC60 v in ionic compounds MexC60 are wide and their width decreases with temperature. A model of paramagnetic centers and an empirical formula relating g-factor to valence have been given.

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“…(Prasad et al, 2000;Smith et al, 2009). The gvalue of graphite was determined to be 2.003 and was almost independent of the measured temperatures between 100 K and 300 K (Matsubara et al, 1991). When graphite was milled to powder (10 µm average diameter), the g value was 2.002-2.010 (Matsubara et al, 1996).…”

Section: Surface Area Free Radical and Functional Groups Of Macromomentioning

confidence: 92%

Influence of the Properties of Macromolecular Carbon on de Novo Synthesis of PCDDs, PCDFs, PCBs, and Chlorobenzenes

Fujimori

Nishimura

Oshita

et al. 2014

Aerosol Air Qual. Res.

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We examined the influence of the properties of macromolecular carbon on thermochemical de novo synthesis of toxic chlorinated aromatic compounds (aromatic-Cls), such as polychlorinated dibenzo-p-dioxins (PCDDs), furans (PCDFs), biphenyls (PCBs), and chlorobenzenes (CBzs). Six types of macromolecular carbons were prepared. Some activated carbon samples were modified by chemical solvents, such as nitric acid, hydrogen peroxide, sulfuric acid, and urea solutions, to change the properties of the activated carbon. We characterized six macromolecular carbons by surface area (8.8-1540 m 2 /g), free radicals (N s = not analyzed to 67.0 × 10 19 g -1 , g = 2.0011-2.0098), and functional groups (O-H, C-H, C=O, C=C, C-O, and C-OH). Concentrations of aromatic-Cls at 300-400°C, such as PCDDs, PCDFs, PCBs, and CBzs, were clearly influenced by the type of macromolecular carbon. Their distribution between the ash/gas phases implied that increasing the surface area mainly enhanced the adsorption capacity of macromolecular carbon, while increasing the number of free radicals mainly enhance the reaction activity of macromolecular carbon. The PCDD/PCDF ratio suggested that various modifications of macromolecular carbon contributed to the generation of PCDDs in addition to the catalytic behavior of copper. Under most conditions, the surface area of macromolecular carbon did not have a strong correlation with the generation of PCDDs, PCBs, and CBzs, but it did show have a correlation with the generation of PCDFs. One of the destructive effects of aromatic-Cls resulted from the free radicals in macromolecular carbon. The C=O bond (ca. 1720 cm -1 ) functional group in macromolecular carbon had no strong correlation with the generation of aromatic-Cls, because free radicals had a destructive effect. The functionalities of ether (C-O) or phenolic OH (C-OH) in macromolecular carbon were causative factors in the generation of oxygen-containing aromatic-Cls, such as PCDDs and PCDFs.

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Electron spin resonance in graphite

Cited by 45 publications

References 12 publications

Probing Electron Spin Resonance in Monolayer Graphene

Probing Electron Spin Resonance in Monolayer Graphene

Valence state of paramagnetic centers in fullerenes

Influence of the Properties of Macromolecular Carbon on de Novo Synthesis of PCDDs, PCDFs, PCBs, and Chlorobenzenes

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