Molecular dynamics and the phase transition in solid<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">C</mml:mi></mml:mrow><mml:mrow><mml:mn>60</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>

Tycko, Robert; Dabbagh, G.; Fleming, R. M.; Haddon, Robert C.; Makhija, A. V.; Zahurak, S. M.

doi:10.1103/physrevlett.67.1886

Cited by 496 publications

(247 citation statements)

References 13 publications

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“…During the process of lowering temperature, there is either a phase in which the carbon cluster rotation is inhibited or a distribution of the rotational correlation times. These conclusions are further supported by the NMR relaxation measurement of Coo in the solid state by Tycko and co-workers [138]. …”

Section: Jumps With An Icosahedral Symmetrysupporting

confidence: 55%

Scalar operators in solid-state NMR

Sun

1991

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Section: Jumps With An Icosahedral Symmetrysupporting

confidence: 55%

Scalar operators in solid-state NMR

Sun

1991

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“…Note that the spectrum of solid C 60 is reproduced by a reported shift tensor. 16) Then, we find that the spectra of the SWCNTs have the same characteristic features as those for aromatic carbons having sp 2 hybridization. 7,[17][18][19] The 33 axis should be nearly parallel to the radial direction of the SWCNTs, on the basis of the analogy of aromatic materials and graphite family where the smallest (most shielded) component axis is parallel to the direction of the carbon p z orbital.…”

mentioning

confidence: 68%

¹³C-NMR Shift of Highly Concentrated Metallic and Semiconducting Single-Walled Carbon Nanotubes

et al. 2013

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Single-walled carbon nanotubes (SWCNTs) have novel electronic properties originating from their unique onedimensional (1D) structures. 1) Their electronic properties are well correlated with the geometrical structure represented by the chiral index ðn; mÞ. Such global features were confirmed using several experimental techniques, such as scanning tunneling microscopy, 2,3) optical absorption, 4) and photoemission spectroscopy. 5) The 13 C-NMR technique has also been applied to reveal the unusual electronic properties of SWCNTs. 6-11) However, to our knowledge, NMR observations have been limited to the SWCNT samples mixed with both metallic and semiconducting SWCNTs. This substantially hampered the study of the individual properties of SWCNTs, which sensitively depend on the detailed electronic structure. One such interesting property is the magnetic response or orbital susceptibility as in other carbon network systems. 12,13) In this connection, we report here the first determination of a 13 C-NMR shift tensor, which is closely related to the orbital susceptibility in metallic and semiconducting SWCNTs.The highly concentrated metallic and semiconducting SWCNTs (more than $95%) with a mean diameter of 1.45 nm were prepared by the method described in Ref. 14; the extractions of metallic and semiconducting SWCNTs from pristine SWCNTs, the Arc-SO SWCNT soot (Meijo Nano-Carbon), were accomplished by the density gradient ultracentrifugation (DGU) technique. Each sample was characterized on the basis of photoabsorption (Shimadzu UV-3600), electrical resistance, 15) and powder X-ray diffraction (XRD) at the BL8B station in the Photon Factory facility, KEK, Japan (see Fig. 1). Note that there is no trace of graphitized carbon and ferromagnetic impurity particles in the XRD profiles. This is consistent with the previous magnetization measurement (see Fig. S.3. in Ref. 15).We observed the 13 C isotope of natural abundance (1.1%). Each sample ($18 mg) was sealed in a quartz tube with helium of $1 atm after sufficient evacuation at 800 K. For semiconducting SWCNTs, two samples of different batches, #1 and #2, were examined. The NMR spectra were obtained by Fourier transformation of the latter half of the spin-echo signal that appeared after the =2-pulse sequence, using a phase-coherent pulsed spectrometer. The =2 pulse width was 6.0 s. The radiated rf field frequency was varied over a range of the NMR spectral width of about 20 kHz to examine spectral distortion effects due to the finite pulse widths. The 13 C-NMR shift was determined with respect to the 13 C resonance in tetramethylsilane (TMS).Figure 2 presents 13 C-NMR spectra of the metallic and semiconducting SWCNTs, along with that of solid C 60 obtained at 4.2 K, where the rotational motion of C 60 completely freezes. Note that the spectrum of solid C 60 is reproduced by a reported shift tensor. 16) Then, we find that the spectra of the SWCNTs have the same characteristic features as those for aromatic carbons having sp 2 hybridization. 7,[17][18][19] The 33 axis sho...

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“…13 C NMR line shape and spin-lattice relaxation in fullerite C 60 have been studied in magnetic fields of 1.4 to 9.4 T at temperatures ranging from 100 to 340 K [3,4,5,6]. These experiments clearly demonstrate that the 13 C NMR spectrum of fullerite C 60 in the range 100-340 K is dominated by one type of magnetic interaction, namely, by 13 C magnetic shielding anisotropy, which determines both the line shape and T 1 .…”

Section: Introductionmentioning

confidence: 90%

“…Values of these parameters for fullerite C 60 were determined earlier [3,4,5,6]: σ = 1.43 × 10 −4 (from TMS), δ = −1.1 × 10 −4 , η = 0.24. Here, we use ω 0 = 2π × 75.4 MHz.…”

Section: Spin-lattice Relaxation Timementioning

confidence: 99%

Spin-rotation interaction in fulleriteC60

2002

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We report on the 13 C spin-lattice relaxation times in polycristalline fullerite C60 measured over the temperature range 295 K to 1000 K. At temperatures above 470 K, spin-lattice relaxation is dominated by the spin-rotation interaction. From the analysis of temperature dependence of T1( 13 C), the spin-rotation constant is determined using J-and M-models of rotational diffusion: CJ ≃ −51 Hz, CM ≃ −29 Hz.

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Molecular dynamics and the phase transition in solidC60

Cited by 496 publications

References 13 publications

Scalar operators in solid-state NMR

Scalar operators in solid-state NMR

¹³C-NMR Shift of Highly Concentrated Metallic and Semiconducting Single-Walled Carbon Nanotubes

Spin-rotation interaction in fulleriteC60

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Molecular dynamics and the phase transition in solidC60

Cited by 496 publications

References 13 publications

Scalar operators in solid-state NMR

Scalar operators in solid-state NMR

13C-NMR Shift of Highly Concentrated Metallic and Semiconducting Single-Walled Carbon Nanotubes

Spin-rotation interaction in fulleriteC60

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¹³C-NMR Shift of Highly Concentrated Metallic and Semiconducting Single-Walled Carbon Nanotubes