We report results of 75As nuclear magnetic resonance (NMR) experiments on a self-flux grown highquality single crystal of SrFe 2As 2. The NMR spectra clearly show sharp first-order antiferromagnetic (AF) and structural transitions occurring simultaneously. The behavior in the vicinity of the transition is compared with our previous study on BaFe 2As 2. No significant difference was observed in the temperature dependence of the static quantities such as the AF splitting and electric quadrupole splitting. However, the results of the NMR relaxation rate revealed difference in the dynamical spin fluctuations. The stripe-type AF fluctuations in the paramagnetic state appear to be more anisotropic in BaFe 2As 2 than in SrFe 2As 2.
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