We first show results of (NMR-1/T1)-T curves of LaFeAsO 1-xFx samples with various x values. It does not have the coherence peak and absolute values of dlog(1/T1)/d log(T/T c) shows the dome shaped x dependence with a maximum at the optimum x value. Considering the T dependent energy broadening of quasi-particles and magnetic susceptibility below Tc, we show that the nonexistence of the coherence peak cannot necessarily be regarded as the evidence for the S ± symmetry of the order parameter. We also present NMR data on the superconducting Ca-Fe-Pt-As system recently found by Kakiya et al. 75As-NMR spectra taken for single crystals of the system indicate clear evidence that Pt atoms are doped into the FeAs conducting layers consistently with the results of the structure analyses, indicating that the superconductivity survives even in the existence of strong impurity scattering of the conduction electrons.
|ジャーナル||Journal of Physics: Conference Series|
|出版ステータス||Published - 2012 1 1|
|イベント||26th International Conference on Low Temperature Physics, LT 2011 - Beijing, China|
継続期間: 2011 8 10 → 2011 8 17
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