Naslov
75As Nuclear Magnetic Resonance studies of Superconducting LaO1-xFxFeAs
(75As Nuclear Magnetic Resonance studies of superconducting LaO1-xFxFeAs)

Autori
Grafe, Hans-Joachim ; Paar, Dalibor ; Lang, Guillaume ; Wolter, Anja ; Manthey, Katarina ; Hammerath, Franziska ; Curro, Nick J. ; Büchner, Bernd

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
6th INTERNATIONAL CONFERENCE OF THE STRIPES SERIES, Quantum Phenomena in Complex Matter / Bianconi, A - Erice : SUPERSTRIPES-ONLUS and ETTORE MAJORANA FOUNDATION AND CENTRE FOR SCIENTIFIC CULTURE, 2008, 75-75

Skup
6th INTERNATIONAL CONFERENCE OF THE STRIPES SERIES, Quantum Phenomena in Complex Matter

Mjesto i datum
Erice, Italija, 26.07.2008. - 01.08.2008

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
high temperature superconductivity; pseudogap; nuclear magnetic resonance and relaxation; oxypnictides

Sažetak
We have performed 75As Nuclear Magnetic Resonance (NMR* and Nuclear Quadrupole Resonance (NQR* measurements on powders and aligned powders of the new LaO 1-x FxFeAs superconductor [1]. In the normal state, we find a strong doping dependence of the As NQR frequency that increases with increasing F doping, similar to the 17O quadrupole frequency in the high Tc cuprates, suggesting that the As quadrupole frequency is a measure of the charge carrier doping. From the As NMR experiments on aligned powders, we find a strong temperature dependence of the spin shift and Korringa behavior of the spin lattice relaxation rate. In the superconducting state, we find evidence for line nodes in the superconducting gap and spin-singlet pairing. Our measurements reveal a strong anisotropy of the spin lattice relaxation rate, which suggest that superconducting vortices contribute to the relaxation rate when the field is parallel to the c-axis but not for the perpendicular direction.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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