Nuclear relaxation and impurity magnetism in superconducting La/sub 1 - c/Gd/sub c/Al2 and La/sub 1 - c/Ce/sub c/Al2

The 139La spin-lattice relaxation rate in the normal and superconducting states of La1/sub - c/Gd/sub c/Al2 and La1/sub - c/Ce/sub c/Al2 alloys has been studied as a probe of the effect of magnetic impurities on superconducting quasiparticle excitations in these systems. Comparison of the experimental data with the theory of pair breaking by magnetic impurities verifies the predicted broadening of the peak in the spectrum of quasiparticle excitations. The dependence of the relaxation rate on the strength of the coupling between conduction electrons and impurities is not fully resolved in the present experiments