Multiferroic properties of sputtered BiFe O3 thin films

A cosputtering method was used to deposit BiFe O3 thin films on PtTiSi O2 Si substrates. It was confirmed as a polycrystalline film with a tetragonal crystal structure in the annealed state. Both Fe2+ and Fe3+ ions were found to coexist in the film. The leakage current density is as low as 10-3 A cm2 at 120 kVcm. This sputtered film shows multiferroic properties exhibiting a saturated ferroelectric loop with a large remnant polarization of 37 μC cm2 and a saturated ferromagnetic loop with saturation magnetization of 21 emu cm3 at room temperature.