  The development of functional composite nanomaterials based on graphene and
metal nanoparticles (NPs) is currently the subject of intense research
interest. In this study we report the preparation of novel type of graphene/Sn
and graphene/SnOx (1 < x < 2) hybrid nanostructures and their investigation by
scanning probe methods. First, we prepare Sn NPs by evaporating 7 - 8 nm tin on
highly oriented pyrolytic graphite substrates. Graphene/Sn nanostructures are
obtained by transferring graphene on top of the tin NPs immediately after
evaporation. We show by scanning tunnelling microscopy (STM) and spectroscopy
(STS) that tin NPs reduce significantly the environmental p-type doping of
graphene. Furthermore, we demonstrate by low-temperature STM and STS
measurements that superconductivity is induced in graphene, either directly
supported by Sn NPs or suspended between them. Additionally, we prepare SnOx
NPs by annealing the evaporated tin at 500 ${^o}$C. STS measurements performed
on hybrid graphene/SnOx nanostructures reveal the electronic band gap of SnOx
NPs. The results can open new avenues for the fabrication of novel hybrid
superconducting nanomaterials with designed structures and morphologies.
