  The magneto-transport properties of nanocomposite C:Co (15 and 40 at.% Co)
thin films are investigated. The films were grown by ion beam co-sputtering on
thermally oxidized silicon substrates in the temperature range from 200 to 500
degC. Two major effects are reported: (i) a large anomalous Hall effect
amounting to 2 \mu ohm cm, and (ii) a negative magnetoresistance. Both the
field-dependent resistivity and Hall resistivity curves coincide with the
rescaled magnetization curves, a finding that is consistent with spin-dependent
transport. These findings suggest that C:Co nanocomposites are promising
candidates for carbon-based Hall sensors and spintronic devices.
