NMR OF CU SATELLITES IN THE KONDO ALLOY CUCR

Using pulsed NMR techniques, resonances of Cu nuclei which are near neighbors to Cr impurities (c=100 and 200 ppm) in CuCr (cursive-theta sign k∼3 K) have been studied in the temperature range 1-4 K and applied fields Ho=20-125 kOe. At the highest fields and lowest temperatures the satellite shifts approach saturation. Above ∼40 kOe the spin-lattice relaxation rate T1-1 is proportional to T/Ho2, indicating that the dominant relaxation mechanism arises from transverse fluctuations of a polarized local moment. The measured rates yield a local-moment/conduction-electron exhange interaction ∥Jρ∥/g=0.30, where g is the Cr g-value. Below ∼40 kOe T 1-1 appears to be slightly enhanced in comparison with the high-field behavior, but becomes field independent below ∼30 kOe. Both effects are attributed to Kondo anomalies.