  We report very low temperature magnetoconductance DeltaG measurements on
graphene devices with the magnetic field H applied parallel to the carbon
sheet. The DeltaG(H) signal depends on the gate voltage Vg and its sign is
related with the universal conductance fluctuations. When the magnetic field is
swept at fast rates, DeltaG displays hysteresis loops evident for different
sizes and at different transport regimes of the devices. We attribute this to
the magnetization reversal of paramagnetic centres in graphene layer, which
might originate from defects in our devices.
