TY - JOUR
T1 - Systematic A 75 s NMR study of the dependence of low-lying excitations on F doping in the iron oxypnictide LaFeAsO1-x Fx
AU - Nakai, Yusuke
AU - Kitagawa, Shunsaku
AU - Ishida, Kenji
AU - Kamihara, Yoichi
AU - Hirano, Masahiro
AU - Hosono, Hideo
PY - 2009/6/11
Y1 - 2009/6/11
N2 - We report A 75 s NMR studies on LaFeAs (O1-x Fx) (0≤x≤0.14). At x=0.04 near the phase boundary, from resistivity, spin-lattice relaxation rate 1/ T1, and NMR spectrum measurements, we found weak magnetic order at TN □30 K. Antiferromagnetic (AFM) fluctuations proved through 1/ T1 are suppressed significantly with F doping, and pseudogap behavior without pronounced AFM fluctuations is observed at x=0.11 where TC is maximum. This significant suppression of 1/ T1 T upon F doping while TC remains nearly unchanged suggests that low-energy AFM fluctuations probed with A 75 s NMR do not play a crucial role in the superconductivity.
AB - We report A 75 s NMR studies on LaFeAs (O1-x Fx) (0≤x≤0.14). At x=0.04 near the phase boundary, from resistivity, spin-lattice relaxation rate 1/ T1, and NMR spectrum measurements, we found weak magnetic order at TN □30 K. Antiferromagnetic (AFM) fluctuations proved through 1/ T1 are suppressed significantly with F doping, and pseudogap behavior without pronounced AFM fluctuations is observed at x=0.11 where TC is maximum. This significant suppression of 1/ T1 T upon F doping while TC remains nearly unchanged suggests that low-energy AFM fluctuations probed with A 75 s NMR do not play a crucial role in the superconductivity.
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U2 - 10.1103/PhysRevB.79.212506
DO - 10.1103/PhysRevB.79.212506
M3 - Article
AN - SCOPUS:67650035186
SN - 1098-0121
VL - 79
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 21
M1 - 212506
ER -