We report 75As nuclear magnetic resonance studies on an underdoped single-crystal Ba 0.77K 0.23Fe 2As 2 with T c=16.5 K. Below T N=46 K, the NMR peaks for Hc split and those for Ha shift to higher frequencies, which indicates that an internal magnetic field along the c axis develops below T N. The spin-lattice relaxation rate 1/T 1 measured at the shifted peak with Ha, which experiences the internal field, shows a distinct decrease below T c(μ 0H=12T)=16 K, following a T3 relation at low temperatures. Our results show unambiguously that antiferromagnetic order and superconductivity coexist microscopically. The unusual superconducting state with the coexisting magnetism is highlighted.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - Nov 5 2012|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics