Enhanced ferroelectricity in Ti-doped multiferroic BiFeO_3 thin films

摘要

Ti~(4+) ion-doped BiFeO_3 thin films were prepared by sol-gel spin-coating technique on (111)Pt/Ti/SiO_2/Si substrates. X-ray diffraction and scanning electron microscope revealed the single phase, and good surface and cross-section morphologies of the films, respectively. Leakage current density measurement indicated that the quality of the BiFeO_3 films was improved by Ti~(4+) doping. By introducing a small amount of Ti ions into the sol-gel solution-processed BiFeO_3 films, large enhancement in both remnant and saturation polarizations of the doped-BiFeO_3 films in comparisons with the undoped BiFeO_3 films was observed, due to the reduced leakage current, stabilization of the ferroelectric distortion by Ti~(4+), and more homogenous microstructure.