Abstract
We present -NMR measurements on samples with sulfur content , 9%, 15%, and . Twinned nematic domains are observed in the NMR spectrum for all samples except . The NMR spin-lattice relaxation rate shows that antiferromagnetic (AFM) fluctuations are initially enhanced between and , but are strongly suppressed for higher values. The observed behavior of the AFM fluctuations parallels the superconducting transition temperature in these materials, providing strong evidence for the primary importance of AFM fluctuations for superconductivity, despite the presence of nematic quantum criticality in the system.
- Received 9 February 2018
- Revised 12 July 2018
DOI:https://doi.org/10.1103/PhysRevB.98.020507
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