We present nuclear magnetic resonance evidence that very slow (≤1 MHz) spin fluctuations persist into the overdoped regime of Ba(Fe1-xRhx)2As2 superconductors. Measurements of the As75 spin echo decay rate, obtained both with Hahn Echo and Carr Purcell Meiboom Gill pulse sequences, show that the slowing down of spin fluctuations can be described by short-range diffusive dynamics, likely involving domain walls motions separating (π/a,0) from (0,π/a) correlated regions. This slowing down of the fluctuations is weakly sensitive to the external magnetic field and, although fading away with doping, it extends deeply into the overdoped regime.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics