Investigation of structural, electrical and multiferroic properties of Co-doped Aurivillius Bi6Fe2Ti3O18 thin films

In this study, the structural, electrical and multiferroic properties of Bi6Fe2Ti3O18 and Bi6Fe1.5Co0.5Ti3O18−δ thin films were investigated. A chemical solution deposition method was used to prepare the thin films on Pt(111)/Ti/SiO2/Si(100) substrates. Both of the thin films crystallized with single phase Aurivillius orthorhombic structures were confirmed by means of X-ray diffraction and Raman spectroscopy studies. X-ray diffraction study further revealed Co2+-ion doping to have a significant influence on the orientation of the Bi6Fe2Ti3O18 thin film. Electrical studies revealed that the leakage current density of the Bi6Fe1.5Co0.5Ti3O18−δ thin film was about two orders of magnitude lower than that of the Bi6Fe2Ti3O18 thin film. An enhanced remnant polarization (2Pr) of 7.4 μC/cm2 and a remnant magnetization (2Mr) of 0.97 emu/cm3 was obtained for the Bi6Fe1.5Co0.5Ti3O18−δ thin film by measuring the ferroelectric and ferromagnetic hysteresis loops at room temperature.