Coupling between 4f and itinerant electrons in SmFeAsO1-xFx (0.15 < x < 0.2) superconductors: an NMR study

G. Prando, P. Carretta, A. Rigamonti +4

${}^{19}$F NMR measurements in SmFeAsO${}_{1-x}$F${}_x$, for $0.15\le x\le 0.2$, are presented. The nuclear spin-lattice relaxation rate $1/T_1$ increases upon cooling with a trend ana…