Multiferroic 0.7BiFeO3-0.3PbTiO3 thin films prepared by a sol-gel method

Multiferroic 0.7BiFeO3-0.3PbTiO3 (BFO-PT) thin films have been prepared by a sol-gel method on Pt/Ti/SiO2/Si substrates. A strong dielectric dispersion was observed above 10 kHz and a relatively low dielectric loss was found at low frequencies. The BFO-PT thin films exhibit both ferroelectricity and (week) ferromagnetism with Pr = 13.7 μC/cm2 and MS = 3200 A/m at room temperature, confirming the multiferroic properties. The local polar domain structure and ferroelectric switching of the thin films were investigated by piezoresponse force microscopy.