Voltage-controlled magnetoresistance of magnetite film in Fe3O4/Si structure at room temperature

•The large low field negative MR ∼ 4% of Fe3O4 is achieved at 300 K and 500 Oe.•A voltage and angle dependence of MR is observed.•The MR originates from the amplification of the MR of Fe3O4 in the structure.

In this paper, we investigate the voltage-controlled magnetoresistance (MR) of Fe3O4/Si structure prepared with pulsed laser deposition. The temperature dependence of resistance and non-linear I–V curve at room temperature suggest that the measured resistance is strongly influenced by the applied voltage and/or the current. The MR was observed to be dependent upon both the applied voltage and the angle between the magnetic field and the current. A greatly magnified low field negative MR ∼ −4% was achieved at 300 K and 500 Oe up to 3.0 V in the Fe3O4/Si structure, which originated from the release of charge accumulation at the Fe3O4/Si interface under the applied magnetic field due to the negative MR of Fe3O4.