Tunneling magnetoresistance in Fe-oxide film

We fabricate Fe/Fe oxide granular film by DC sputtering and study the magnetic and transport properties in the insulator region. X-ray photoelectron spectroscopy and transmission electron microscopy confirm the coexistence of iron and Fe2O3. Accompanied with the nonlinear I–V curve and magnetic measurement, we investigate mechanism of sizable magnetoresistance in detail and found the spin in the interface has crucial contribution to the spin tunneling process.