▎ 摘　　要

The considerable spin diffusion length and high electron mobility of graphene at room temperature makes it a suitable candidate to improve the spin transport properties of magnetic semiconductors when incorporated in a suitable stoichiometry. Herein, an observation of room-temperature magnetoresistance (MR) properties of reduced graphene oxide (rGO)/cobalt ferrite (CFO) nanocomposites, which are synthesized by chemical methods followed by mixing in different mass ratios, is reported. The magnetic field-dependent electrical resistivity shows a decrease in resistivity with the increase in magnetic field from 0 to 0.5 T, representing a negative MR in our samples. The highest MR of around -1.4% is observed in the 1:1 ratio CFO and rGO nanocomposite, whereas the samples with 2:1 and 3:1 ratio show the MR of approximate to-1%. In the CFO-rGO nanocomposite, the charge transport takes place mainly through the rGO layers due to the insulating nature of the CFO nanoparticles. However, the ferromagnetic moments of the CFO nanoparticles induce electron-spin scattering during the charge transport. The reduction in electron-spin scattering results due to the parallel alignment of the magnetic moments. The alignment of ferromagnetic moments under the external magnetic field has been further confirmed from the magnetocapacitance effect of CFO nanoparticles.