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.