Browse > Article

$^{13}C$ Nuclear Magnetic Resonance Study of Graphite Intercalated Superconductor $CaC_6$ Crystals in the Normal State  

Kim, Sung-Hoon (Department of Physics, Konkuk University)
Kang, Ki-Hyeok (Department of Physics, Konkuk University)
Mean, B.J. (Department of Physics, Konkuk University)
Ndiaye, B. (Department of Physics, Konkuk University)
Lee, Moo-Hee (Department of Physics, Konkuk University)
Kim, Jun-Sung (Department of Physics, Pohang University of Science and Technology)
Publication Information
Progress in Superconductivity / v.12, no.1, 2010 , pp. 51-56 More about this Journal
Abstract
$^{13}C$ NMR (nuclear magnetic resonance) measurements have been performed to investigate the local electronic structure of a superconducting graphite intercalation compound $CaC_6$ ($T_c$ = 11.4 K). A large number of single crystals were stacked and sealed in a quartz tube for naturally abundant $^{13}C$ NMR. The spectrum, Knight shift, linewidth, and spin-lattice relaxation time $T_1$ were measured in the normal state as a function of temperature down to 80 K at 8.0 T perpendicular to the c-axis. The $^{13}C$ NMR spectrum shows a single narrow peak with a very small Knight shift. The Knight shift and the linewidth of the $^{13}C$ NMR are temperature-independent around, respectively, +0.012% and 1.2 kHz. The spin-lattice relaxation rate, $1/T_1$, is proportional to temperature confirming a Korringa behavior as for non-magnetic metals. The Korringa product is measured to be $T_1T\;=\;210\;s{\cdot}K$. From this value, the Korringa ratio is deduced to be $\xi$ = 0.73, close to unity, which suggests that the independent-electron description works well for $CaC_6$, without complications arising from correlation and many-body effects.
Keywords
$CaC_6$; $^{13}C$ NMR; local electronic structure in the normal state; Knight shift; linewidth; $T_1$ rate; $T_1T$;
Citations & Related Records
연도 인용수 순위
  • Reference
1 I. I. Mazin, L. Boeri, O. V. Dolgov, A. A. Golubov, G. B. Bachelet, M. Giantomassi, and O. K. Anderson, Physica C 460-462, 116 (2007).   DOI   ScienceOn
2 G. C. Carter, L. H. Bennett, and D. J. Kahan, Metallic shift in NMR, (Pergamon Press, New York, 1977), p. 15.
3 D. E. MacLaughlin, O. Pena and M. Lysak, Phys. Rev. B 23, 1039 (1981).   DOI
4 N. B. Hannay, T.H. Geballe, B. T. Matthias, K. Andres, P. Schmidt, and D. MacNair, Phys. Rev. Lett. 14, 225(1965).   DOI
5 M. S. Dresselhaus and G. Dresselhaus, Adv. in Phys., 51, 1 (2002).   DOI   ScienceOn
6 J. E. Weller, M. Ellerby, S. S. Saxena, R. P. Smith, N. T. Skipper, Nature Physics, 1, 39 (2005).   DOI   ScienceOn
7 D. G. Hinks, D. Rosenmann, H. Claus, M. S. Bailey, and J. D. Jorgensen, Phys. Rev. B 75, 014509 (2007).   DOI   ScienceOn
8 N. Emery, C. Herold, M. d'Astuto, V. Garcia, C. Bellin, J. F. Mareche, P. Lagrange, and G. Loupias, Phys. Rev. Lett. 95, 087003 (2005).   DOI   ScienceOn
9 G. Lamura, M. Aurino, G. Cifariello, E. D. Gennaro, Andreone, N. Emery, C. Herold, J.-F. Mareche, and P. Lagrange, Phys. Rev. Lett. 96, 107008 (2006).   DOI   ScienceOn
10 J. S. Kim, R. K. Kremer, L. Boeri, and F. S. Razavi, Phys. Rev. Lett. 96, 217002 (2006).   DOI   ScienceOn
11 C. P. Slichter, Principles of Magnetic Resonance (Springer Verlag, Berlin, 1989).
12 W. D. Knight, Solid State Phys. 2, 93 (1956).
13 G. C. Carter, L. H. Bennett and D. J. Kahan, Prog. Mat. Sci. 20, 295 (1977).
14 R. E. Watson and A. J. Freeman, Hyperfine Interactions, edited by A. J. Freeman and R. B. Frankel (Academic Press, New York, 1967), p. 53.
15 R. G. Barnes and E. D. Jones, Solid State Commun. 5, 285 (1967).   DOI   ScienceOn
16 Narath and H. T.Weaver, Phys. Rev. 175, 373 (1968).   DOI
17 J. Korringa, Physica (Utrecht) 16, 601 (1950).   DOI   ScienceOn