Magnetic hyperfine field atIn111probes in the topmost atomic layer of Ni(111) surfaces

The magnetic hyperfine field was measured at ${}_{}{}^{111}{}_{}{}^{}\mathrm{In}$ ${(}^{111}$Cd) probes on Ni(111) surfaces utilizing the perturbed γγ-angular-correlation method. Over the entire temperature range up to the Curie temperature the magnetic hyperfine field at probes in the topmost monolayer was found to be reduced as compared to the field for probes in the 3.5th monolayer and in bulk. The probe lattice location was inferred from the structural information derived through simultaneous measurement of the electric-field-gradient tensor acting at probe nuclei.