In magnetically polarized ultrathin Pd films with (111) orientation, grown on a Ni(001) single crystal, static magnetic hyperfine fields were measured at the interface using perturbed angular correlation spectroscopy. The structural arrangement of the Pd atoms with respect to the Ni substrate differs from one Pd atom to the next, leading to varying $3d-4d$ electron hybridizations. This gives rise to a broad distribution of magnetic hyperfine fields at Rh nuclei, seen in experiments with the self-element probe ${}^{100}\mathrm{Pd}{/}^{100}\mathrm{Rh}$, while discrete field values were found for the voluminous impurity probe ${}^{111}$Cd.

• Received 30 September 1997

DOI:https://doi.org/10.1103/PhysRevLett.80.2721