Frandsen, Benjamin A.Taddei, Keith M.Bugaris, Daniel E.Stadel, RyanYi, MingAcharya, AraniOsborn, RaymondRosenkranz, StephanChmaissem, OmarBirgeneau, Robert J.2019-01-092019-01-092018Frandsen, Benjamin A., Taddei, Keith M., Bugaris, Daniel E., et al.. "Widespread orthorhombic fluctuations in the (Sr,Na)Fe2As2 family of superconductors." <i>Physical Review B,</i> 98, no. 18 (2018) American Physical Society: https://doi.org/10.1103/PhysRevB.98.180505.https://hdl.handle.net/1911/105019We report comprehensive pair distribution function measurements of the hole-doped iron-based superconductor system Sr1−xNaxFe2As2. Structural refinements performed as a function of temperature and length scale reveal orthorhombic distortions of the instantaneous local structure across a large region of the phase diagram possessing average tetragonal symmetry, indicative of fluctuating nematicity. These nematic fluctuations are present up to high doping levels (x≳0.48, near optimal superconductivity) and high temperatures (above room temperature for x=0, decreasing to 150 K for x=0.48), with a typical length scale of 1–3 nm. This work highlights the ubiquity of nematic fluctuations in a representative iron-based superconductor and provides important details about the evolution of these fluctuations across the phase diagram.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Journal articlePhysRevB.98.180505https://doi.org/10.1103/PhysRevB.98.180505