Monolayer-resolved magnetic and electric hyperfine fields at Ni(111) surfaces

The magnetic hyperfine field and the electric-field gradient of free single-crystal Ni(111) surfaces have been investigated with the perturbed yy angular correlation (PAC) method using radioactive 111 In probe atoms with a concentration of 10 −4 ML. The hyperfine fields have been measured at probe atoms in the top-most surface monolayer, in the 3.5th monolayer and in bulk over a temperature range from 80 K up to the Curie temperature.