We have performed 75As nuclear magnetic resonance measurements on a single crystal of the hole-doped superconductor Ba0.72K 0.28Fe2As2 (Tc = 31.5 K). The spin-lattice relaxation rate 1/T1 decreases below Tc with no coherence peak and shows a step-wise variation at low temperatures, which is indicative of multiple superconducting gaps. In the normal state, we find that Fe antiferromagnetic spin fluctuations are anisotropic.
- Anisotropic spin fluctuations
- BaK FeAs
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering