<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">C</mml:mi></mml:mrow><mml:mprescripts /><mml:mrow /><mml:mrow><mml:mn>13</mml:mn></mml:mrow><mml:mrow /><mml:mrow /></mml:mmultiscripts></mml:mrow></mml:math>NMR hyperfine couplings,<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>T</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub></mm

Pennington, C. H.; Stenger, V. Andrew; Recchia, Charles H; Hahm, C.; Gorny, Krzysztof R.; Nandor, V. A.; Buffinger, D. R.; Lee, S. M.; Ziebarth, R. P.

doi:10.1103/physrevb.53.r2967

Cited by 18 publications

(15 citation statements)

References 18 publications

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“…The good fit of the solid curve also demonstrates that the density-of-states parameters obtained from other independent experiments can be used successfully to understand the lattice-constant dependence of 1/T 1 T. These same parameters also provide a rather complete picture of superconductivity in the weak-coupling limit of BCS theory (see text, and Stenger et al, 1995). course, in powder samples, the magnetic field will take on all possible orientations with respect to the zЈ axes with equal probability per unit solid angle. Nevertheless Pennington et al (1995) have found a way to extract the anisotropy of T 1 and thus to test the dipolar relaxation proposal of Antropov et al and, in fact, to test the Korringa relation.…”

Section: Comparison Of 1/t 1 T and The Knight Shift From The Korringamentioning

confidence: 99%

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Nuclear magnetic resonance ofC60and fulleride superconductors

1996

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The alkali-doped solid materials A 3 C 60 (where A is an alkali metal), which are superconductors with transition temperatures among the highest known apart from the high-T c cuprates, are among the most exciting outgrowths of the discovery of the family of fullerene molecules. The structural, electronic, and superconducting properties of the alkali fullerides have been subjects of great controversy. In this article the authors review nuclear magnetic resonance (NMR) investigations of the alkali fullerides and of undoped C 60 . They show that, although the NMR data certainly provide evidence for unusual static and dynamic structural properties, there is little evidence for unusual normal-and superconducting-state electronic properties, such as strong correlations in the normal state or nonphononic mechanisms of superconductivity. [S0034-6861(96)

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Section: Comparison Of 1/t 1 T and The Knight Shift From The Korringamentioning

confidence: 99%

“…To test this prediction, Pennington et al (1995) measured T 1 as a function of frequency for a fixed applied field, for Rb 2 CsC 60 . Figure 51 shows these results for T=80 K. From the figure it is clear that although there is substantial anisotropy, it is not as large as 2.5 to 1.…”

Section: Comparison Of 1/t 1 T and The Knight Shift From The Korringamentioning

confidence: 99%

Nuclear magnetic resonance ofC60and fulleride superconductors

1996

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“…A deeper understanding of the relationship between 13 C shifts and conductivity (and superconductivity) is coming from the analysis of temperature-dependent data. 333,334 The modest temperature dependence of the ca. 180 ppm shifts for A 4 C 60 (A ) K, Rb) 330,335 (decreasing to 177 at 4 K) is particularly intriguing because these materials are not metals and yet the shifts are considerably downfield of the values that might be expected for a C 60 4-ion with an S ) 0 ground electronic state (ca.…”

Section: E Knight Shift In a 3 C 60mentioning

confidence: 99%

Discrete Fulleride Anions and Fullerenium Cations

2000

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His research interests include reactive cation and superacid chemistry with inert carborane counterions, ionic liquids, bioinorganic chemistry, spin-coupling phenomena, fullerene chemistry, and new carbon-or porphyrin-based materials. He is a Sloan Fellow, a Dreyfus Teacher−Scholar Awardee, and a Guggenheim Fellow. Robert Bolskar received his B.S. degree in Chemistry from Carroll College in Waukesha, WI, in 1992. He earned his Ph.D. degree at the University of Southern California in Los Angeles under the direction of Christopher Reed in 1997, investigating the synthetic redox chemistry of fullerene anions and cations. In 1998 he moved to the University of California, Riverside, as Managing Research Associate. He is currently Senior Chemist at TDA Research in Wheat Ridge, CO. His research interests include the chemistry and physics of fullerene compounds, supramolecular chemistry, strongly oxidizing systems, and electrophilic cations.

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“…22 In a system with magnetic disorder (e.g., a spin glass), spin fluctuation rates are expected to vary randomly over the material, so that the nuclear spin-lattice relaxation rate is distributed. The nuclear magnetization recovery function M͑t͒ then is the spatial average result of the local relaxation functions, i.e., M͑t͒ recovers after saturation according to 23 …”

Section: A Spin-lattice Relaxation Functionsmentioning

confidence: 99%

Si29nuclear spin-lattice relaxation inCePtSi1−
Young¹,
MacLaughlin
²
,
Rose
³

et al. 2004
Phys. Rev. B
2
0
4
0
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29 Si nuclear spin-lattice relaxation measurements have been performed in the heavy-fermion alloys CePtSi 1−x Ge x , x = 0 and 0.1, in order to study spin dynamics near a magnetic instability. The spin-relaxation curves for both x = 0 and x = 0.1 are found to fit to a stretched exponential slightly better than a single exponential function, which suggests that the relaxation rates are inhomogeneous to some extent, due to structural disorder. Within experimental resolution, the relaxation curve is in agreement with the theoretical curve calculated from the Kondo-disorder model. The temperature-dependent relaxation rate 1 / T 1 follows the Korringa relation in CePtSi below 4 K, but not in CePtSi 0.9 Ge 0.1 . This means that Fermi-liquid and non-Fermiliquid excitations appear in x = 0 and x = 0.1 samples, respectively, which agrees with the results from specific heat experiments. The effective moments of Ce 3+ ions in CePtSi 1−x Ge x for directions parallel and perpendicular to the c axis, calculated from the crystalline electric field (CEF) levels, explain the anisotropy in the observed susceptibilities, hyperfine coupling constants, and spin-lattice relaxation rates. The magnitude of the CEFcorrected Korringa products for the two samples shows the same order as the expected value for a Fermi gas, which indicates that no obvious spin-correlated fluctuations or magnetic order are present. This seems to disagree with the Griffiths phase model, in which magnetic clusters are spatially-extended objects containing many spins.

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C13NMR hyperfine couplings,T1

Cited by 18 publications

References 18 publications

Nuclear magnetic resonance ofC60and fulleride superconductors

Nuclear magnetic resonance ofC60and fulleride superconductors

Discrete Fulleride Anions and Fullerenium Cations

Si29nuclear spin-lattice relaxation inCePtSi1−
Young¹,
MacLaughlin
²
,
Rose
³

et al. 2004
Phys. Rev. B
2
0
4
0
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C13NMR hyperfine couplings,T1

Cited by 18 publications

References 18 publications

Nuclear magnetic resonance ofC60and fulleride superconductors

Nuclear magnetic resonance ofC60and fulleride superconductors

Discrete Fulleride Anions and Fullerenium Cations

Si29nuclear spin-lattice relaxation inCePtSi1−Young1, MacLaughlin2, Rose3 et al. 2004Phys. Rev. B2040View full textAdd to dashboardCite

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Si29nuclear spin-lattice relaxation inCePtSi1−
Young¹,
MacLaughlin
²
,
Rose
³

et al. 2004
Phys. Rev. B
2
0
4
0
View full text Add to dashboard Cite