TY - JOUR
T1 - Anisotropic spin fluctuations and multiple superconducting gaps in hole-doped Ba0.72K0.28Fe2As2
T2 - NMR in a single crystal
AU - Matano, K.
AU - Li, Z.
AU - Sun, G. L.
AU - Sun, D. L.
AU - Lin, C. T.
AU - Ichioka, M.
AU - Zheng, Guo Qing
PY - 2009/7/1
Y1 - 2009/7/1
N2 - We report the75As-NMR study on a single crystal of the hole-doped iron-pnictide superconductor Ba0.72K0.28Fe 2As2(Tc = 31.5 K). We find that the Fe antiferromagnetic spin fluctuations are anisotropic and are weaker compared to underdoped copper-oxides or cobalt-oxide superconductors. The spin lattice relaxation rate 1/T1 decreases below Tc with no coherence peak and shows a stepwise variation at low temperatures, which is indicative of multiple superconducting gaps, as in the electron-doped Pr(La)FeAsO 1-xFx. Furthermore, no evidence was obtained for a microscopic coexistence of a long-range magnetic order and superconductivity.
AB - We report the75As-NMR study on a single crystal of the hole-doped iron-pnictide superconductor Ba0.72K0.28Fe 2As2(Tc = 31.5 K). We find that the Fe antiferromagnetic spin fluctuations are anisotropic and are weaker compared to underdoped copper-oxides or cobalt-oxide superconductors. The spin lattice relaxation rate 1/T1 decreases below Tc with no coherence peak and shows a stepwise variation at low temperatures, which is indicative of multiple superconducting gaps, as in the electron-doped Pr(La)FeAsO 1-xFx. Furthermore, no evidence was obtained for a microscopic coexistence of a long-range magnetic order and superconductivity.
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U2 - 10.1209/0295-5075/87/27012
DO - 10.1209/0295-5075/87/27012
M3 - Article
AN - SCOPUS:70349697058
SN - 0295-5075
VL - 87
JO - Lettere Al Nuovo Cimento
JF - Lettere Al Nuovo Cimento
IS - 2
M1 - 27012
ER -