Identifying the electron spin resonance of conduction electrons in alkali doped SWCNTs

Abstract

We study the electron spin resonance (ESR) signal of pristine and potassium doped SWCNTs. We identify signals of a superparamagnetic background, a low intensity impurity, and of the conduction electron spin resonance (CESR). The latter only appears upon the alkali atom doping. To identify the CESR signal, we critically assess whether it could come from residual graphitic carbon, which we clearly exclude. We give accurate values for the signal intensities and the corresponding concentration of spins and for the g-factors. The CESR signal intensity allows to determine the density of states on the SWCNT assembly.

Electronic properties of pristine and modified single-walled carbon nanotubes

“…¿ÎÇÍÕÓÑÐÐÞÇ ÔÄÑÌÔÕÄÂ Ë âÄÎÇÐËÇ ÄÑÊÐËÍÐÑÄÇÐËâ ÒÇÓÇ-ÐÑÔ ÊÂÓâAE İ³¯´, ËÐÕÇÓÍÂÎËÓÑÄÂÐÐÞØ AEÑÐÑÓÂÏË Ë ÂÍÙÇÒÕÑÓÂÏË àÎÇÍÕÓÑÐÑÄ, ÃÞÎË ËÊÖÚÇÐÞ ÏÇÕÑAEÂÏË ÔÒÇÍÕ-ÓÑÔÍÑÒËË ¬² [113, 172 ë 174, 186, 192, 202, 205, 210, 213, 218 ë 220], ÑÒÕËÚÇÔÍÑÌ ÔÒÇÍÕÓÑÔÍÑÒËË [35,113,183,190,209,221,222], ÔÒÇÍÕÓÑÔÍÑÒËË ÒÑÕÇÓß àÐÇÓÅËË àÎÇÍÕÓÑÐÑÄ [177,188,189,191,198,209,222,223], àÎÇÍÕÓÑÐÐÑÅÑ ÔÒËÐÑÄÑÅÑ ÓÇÊÑÐÂÐÔ [181,182,197,224,225], ² ¶¿³ [184,185,194,195,199,200],  ÕÂÍÉÇ Ô ÒÑÏÑÜßá ËÊÏÇÓÇÐËÌ ÕÓÂÐÔÒÑÓÕÐÞØ ÔÄÑÌÔÕÄ [173,176,178,187,222,226]. ¢ÞÎÑ ÒÑÍÂÊÂÐÑ, ÚÕÑ ÒÓË ËÐÕÇÓÍÂÎËÓÑÄÂÐËË°³¯´ÖÓÑÄÇÐß ¶ÇÓÏË ÐÂÐÑÕÓÖÃÑÍ ÏÑÉÇÕ ÔÏÇÜÂÕßÔâ РÄÇÎËÚËÐÖ AEÑ 1,3 ࣠[193].…”

Magnetic properties of carbon nanotube poly(ether-ester) nanocomposites

“…2. 10,14,15,17 In the latter case, the formation of a large number of localized spins with spin susceptibility exceeding that of the conduction electron spin system, results in the effective reduction in the anisotropic conduction ESR spectrum of MWNTs, especially at low temperatures. 2͑a͔͒ and the temperature dependence of the static magnetization ͓Fig.…”

“…1,2 Efficient dispersion and interfacial stress transfer between CNTs and the surrounding polymer are major challenges for the production of CNT reinforced nanocomposites. [8][9][10][11][12][13][14][15][16][17] However, apart from the utilization of the highly anisotropic diamagnetic susceptibility of CNTs ͑Ref. However, such functionalization may modify the electronic properties of CNTs through both charge transfer and defect formation 7 and compromise the composite's performance.…”

Advances in tailoring the electronic properties of single-walled carbon nanotubes

“…These techniques include electron energy loss spectroscopy [185,195,196,198,205,216,223,224], X-ray photoelectron spectroscopy [58,192,201,202,206,207], Raman spectroscopy [163, 180-182, 193, 199, 209, 211, 217, 225-228], optical spectroscopy [163,191,197,213,216,224,229], electron spin resonance [189,190,204,230,231], and transport measurements [180,184,186,194,224,232]. T  metals [200].…”