⁷⁵As NMR study of the oriented pnictide superconducting compound NdFeAsO_0.83F_0.17

Magnetization and ⁷⁵As nuclear magnetic resonance (NMR) measurements in the superconductor NdFeAsO_0.83F_0.17 (T_C~46 K) are performed in order to investigate the effect of the Nd 4f electrons in the superconducting property. The magnetization curve displays a Nd 4f moments generated Curie-Weiss signal in the field of 7 T. ⁷⁵As NMR spectra in the oriented sample (H₀‖ab) are recorded at 7 T in the temperature range 10–300 K and temperature dependent ⁷⁵As NMR shift, K_ab has been obtained. The K_ab curve shows a Curie-Weiss type contribution. The magnitude of hyperfine field, H_hf (4.4 kOe/μ_B) estimated from the K_ab vs χ plot indicates a non-negligible RKKY-type interaction between localized Nd 4f moments mediated by itinerant Fe 3d electrons.