  We report on the observation of anisotropic magnetoresistance (AMR) in
vertical asymmetric nano-contacts (NCs) made through AlO$_x$ nano-oxide layer
(NOL) formed by ion-assisted oxidation method in the film stack of
Co/AlO$_x$-NOL/Pt. Analysis of NC formation was based on \emph{in situ}
conductive atomic force microscopy and transmission electron microscopy.
Depending on the purity of NCs from Al contamination, we observed up to 29% AMR
ratio at room temperature.
