  The results of measurements of XPS spectra and magnetic properties of
graphene/Co composites prepared by adding of CoCl$_2$x6H$_2$O diluted in ethyl
alcohol to highly-splitted graphite are presented. XPS Co 2p measurements show
two sets of 2p$_{3/2,1/2}$-lines belonging to oxidized and metallic Co-atoms.
This means that metal in composite is partly oxidized. This conclusion is
confirmed by magnetic measurements which show the presence of the main (from
the metal) and shifted (from the oxide) hysteresis loops. The presence of oxide
layer on the metal surface prevents the metal from the full oxidation and (as
shown by magnetic measurements) provides the preservation of ferromagnetic
properties after long exposure in ambient air which enables the use of
graphene/metal composites in spintronics devices.
