Magnetotransport properties in epitaxial Fe₃O₄(001) thin films with current perpendicular to the plane geometry

We investigated the fundamental transport properties of epitaxial magnetite (Fe₃O₄) films with applied current perpendicular to the plane geometry. The devices with a junction area of 36 μ m 2 were fabricated with TiN/Fe₃O₄/ TM (TM: Ti and Fe) stacking. Both the temperature dependence and the magnetic field dependence of the junction resistance were measured. Most of the resistance properties were independent of whether the electrode was magnetic (Fe) or nonmagnetic (Ti). Below the Verwey point, the junction resistance abruptly increased with decreasing temperature, and the resistance reached maximum at approximately 30 K. The magnetoresistance showed a peak of ∼ 27 at T ≈ 55 K. The observed resistance behavior was consistent with a hopping conduction mechanism with a Coulomb interaction.