Epitaxial SrRuO3/BiFeO3/SrRuO3 heterostructure sputtered at low temperature

SrRuO3(SRO)/BiFeO3(BFO)/SrRuO3 heterostructure is fabricated on the (0 0 1) SrTiO3 substrate by magnetron sputtering, in which BFO film is prepared at a low temperature of 525 °C. The structural and physical properties of the SRO/BFO/SRO heterostructure are investigated. It is found that the whole SRO/BFO/SRO heterostructure is epitaxially grown on SrTiO3 substrate with (0 0 1) orientation. The remanent polarization and coercive field of a typical SRO/BFO/SRO capacitor, measured at 300 kV/cm, are 38.5 μC/cm2 and 120 kV/cm, respectively. The capacitor shows little fatigue up to 1010 switching cycles, and relatively small leakage current density of 7.5×10−4 A/cm2 at 120 kV/cm. Moreover, the SRO/BFO/SRO heterostructure exhibits a weak ferromagnetic behavior with a saturation magnetization of 9.3 emu/cm3 and a coercive field of 338 Oe.