Magnetic Properties in the Normal State of LuNi2B2C Observed by61Ni and11B NMR

The 61 Ni spin-lattice relaxation rate, 61 T 1 -1 , and the Knight shift of a 91% 61 Ni enriched sample of LuNi 2 B 2 C have been measured in the normal state. It was found that 61 ( T 1 T ) -1 shows a Curie-Weiss like behavior, while the Knight shift has a slight temperature dependence. The hyperfine coupling constant is estimated to be 61 A =-16 kOe/µ B , which is an order of magnitude smaller than that due to the 3d-core-polarization mechanism. When the orbital term of the relaxation rate is given by the formula calculated for the tetragonal ( D 2 d ) symmetry at the 61 Ni sites, much larger d-spin term than that expected from the Knight shift is obtained. The Korringa relation is also discussed on the assumption that the hyperfine coupling constant is reduced by a strong s-d admixture, and then the deviation from the Korringa relation for free electrons, K (α), is more than one. This result suggests the significance of the generalized susceptibility, χ( q ), at finite wave vectors.