Calculation of host nuclear relaxation in dilute Kondo alloys for T ? Tk

We present a microscopic calculation of the host nuclear spin-lattice relaxation rate as a function of impurity-host distance r for dilute Kondo alloy at T ? T_k. The net relaxation rate involves two main parts. One, dependent up-on the local conduction electron density of states, exhibits kinematic oscillations which are due to resonant scattering. The other part, due to the impurity spin fluctuations, is shown to dominate the first mechanism allowing the Korringa relation to hold in systems with low T_k (such as Cu:Fe). In A?:Mn both mechanisms are of equal importance, and the net host relaxation rate and the excess Knight shift do not satisfy a Korringa relation.