Physics and Astronomy, Ames Laboratory
Journal or Book Title
Physical Review B
This work presents 75As NMR spin-echo decay rate (1/T2) measurements in Ba(Fe1−xRhx)2As2 superconductors, for 0.041⩽x⩽0.094. It is shown that 1/T2 increases upon cooling, in the normal phase, suggesting the onset of an unconventional very low-frequency activated dynamic. The correlation times of the fluctuations and their energy barriers are derived. The motion is favored at large Rh content, while it is hindered by the application of a magnetic field perpendicular to the FeAs layers. The same dynamic is observed in the spin-lattice relaxation rate, in a quantitatively consistent manner. These results are discussed in the light of nematic fluctuations involving domain wall motion. The analogies with the behavior observed in the cuprates are also outlined.
American Physical Society
Bossoni, L.; Carretta, P.; Halperin, W. P.; Oh, S.; Reyes, A.; Kuhns, P.; and Canfield, Paul C., "Evidence of unconventional low-frequency dynamics in the normal phase of Ba(Fe1-xRhx)(2)As-2 iron-based superconductors" (2013). Physics and Astronomy Publications. 619.