75As NMR Study of Hole-Doped Superconductor Ba1-xKxFe2As2 (Tc = 38K)

Authors :: Fukazawa, H.
Yamazaki, T.
Kondo, K.
Kohori, Y.
Takeshita, N.
Shirage, P. M.
Kihou, K
Miyazawa, K.
Kito, H.
Eisaki, H.
Iyo, A.
Source :: J. Phys. Soc. Jpn. Vol.78 (2009) p033704.
Publication Year :: 2009
Abstract: We report the 75As nuclear magnetic resonance (NMR) measurement of the hole-doped superconductor Ba1-xKxFe2As2 with different lattice parameters and different superconducting volume fractions (Tc = 38K). 75As-NMR spectra revealed that the magnetically ordered and superconducting phases are microscopically separated. The spin-lattice relaxation rate 1/T1 in the normal state reflects the existence of a large two-dimensional antiferromagnetic spin fluctuation. The 1/T1 in the superconducting state down to the lowest measurement temperature T varies close to T^3. In addition, it exhibits no coherence peak just below Tc. This shows a T dependence similar to those of other iron pnictides.<br />Comment: 5 pages, 4 figres, to be published in J. Phys. Soc. Jpn. 78 (2009) No.3 issue