Single-Impurity and Interaction Effect on the Host NMR Linewidth of CuFe in the Kondo State

The effects of single Fe impurities on the Cu-host NMR in CuFe have been measured over a wide range of Fe concentrations up to 45 kOe at 1.65^∘{}K. The additional impurity d-spin conduction-electron spin-correlation effects on the host NMR linewidth originally noted by Golibersuch and Heeger have been shown to be the result of single Fe impurities in the Kondo state; these effects are destroyed at lower applied fields with increasing Fe concentration as a result of Fe-Fe interactions.