  We report on the fabrication, transport measurements, and density functional
theory (DFT) calculations of atomic size contacts made out of gadolinium (Gd).
Gd is known to have local moments mainly associated with $f$ electrons. These
coexist with itinerant $s$ and $d$ bands that account for its metallic
character. Here we explore whether and how the local moments influence
electronic transport properties at the atomic scale. Using both Scanning
Tunneling Microscope (STM) and lithographic Mechanically Controllable Break
Junction (MCBJ) techniques under cryogenic conditions, we study the conductance
of Gd when only few atoms form the junction between bulk electrodes made out of
the very same material. Thousands of measurements shows that Gd has an average
lowest conductance, attributed to an atom-size contact, below $\frac{2e^2}{h}$.
Our DFT calculations for monostrand chains anticipate that the $f$ bands are
fully spin polarized and insulating, and that the conduction may be dominated
by $s$, $p$, and $d$ bands. DFT quantum transport calculations quantitatively
reproduce the experimental results for zero bias and reveal that, while $s-p$
bands are dominant for transport, $d$ orbitals seem to have a relevant
contribution in some cases.
