Structural and ferroelectric properties of Bi4Ti3O12 thin films on IrO2 prepared by rf magnetron sputtering

Abstract.

Bismuth titanate, Bi₄Ti₃O₁₂, thin films were grown on IrO₂/SiO₂/Si substrates by radio-frequency magnetron sputtering. Crystallinity and microstructure of the films were characterized over a wide range of oxygen mixing ratio (OMR) during deposition. X-ray fluorescence spectra reveal that the cation content of the films is dependent upon the OMR, suggesting that control of Bi to Ti ratio is possible by the oxygen content in the sputtering atmosphere. Rutherford backscattering spectrometry measurements also show that oxygen content of the BTO film grown with an OMR = 0.5is close to a stoichiometric phase. In addition, Bi–O bonding chemistry is studied by X-ray photoelectron spectroscopy. Polarization vs. voltage loop shows that remnant polarization, P_r, is +12 μC/cm².