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 10kHz and a relatively low dielectric loss was found at low frequencies. The BFO–PT thin films exhibit both ferroelectricity and (week) ferromagnetism with Pr=13.7μC/cm2 and MS=3200A/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.