Magnetic-moment formation and spin dynamics of isolated 4d ions in palladium.

By applying the perturbed-\ensuremath{\gamma}-ray distribution method following heavy-ion reactions we have observed nonmagnetic behavior for Mo and Tc ions in Pd, but a high local susceptibility for Ru in Pd consistent with the formation of a giant 4d moment. These trends agree with local-spin-density calculations, yielding a magnetic moment for Ru in Pd and a strong ferromagnetic host-d-spin polarization if Ru, Rh, and Pd ions in Pd are locally magnetized by a small magnetic field. We suggest that the occurrence of magnetism and the spin-fluctuation temperatures for 4d and 3d ions in Pd are strongly correlated with the sign and strength of the induced host-d-spin polarization.