Figure 3: Distance dependency of the magnetic interactions in an Fe–Ho pair.
From: Absence of a spin-signature from a single Ho adatom as probed by spin-sensitive tunneling
(a) Constant-current images [(1–8)] of different Fehcp–Ho atom pairs with indicated distances and related ball-models in between. (b) Spectra on the Fehcp atom and (c) the Ho atom for each pair with the 
signal represented by the given colour scale. The spectra have been normalized to a substrate spectrum, divided by their mean value and the colour scaling for Fe and Ho is the same (Istab=3 nA, Vstab=10 mV and Vmod=40 μV).
