Enhanced ferroelectric properties of La-substituted BiFeO3 thin films on LaSrCoO3/Pt/TiO2/SiO2/Si (1 0 0) substrates prepared by the soft chemical method

Bi0.85La0.15FeO3 (BLFO015) thin films were deposited by the polymeric precursor solution on La0.5Sr0.5CoO3 substrates. For comparison, the films were also deposited on Pt bottom electrode. X-ray diffraction data confirmed the substitutions of La into the Bi site with the elimination of all secondary phases under a substitution ratio x = 15% at a temperature of 500 °C for 2 h. A substantial increase in the remnant polarization (Pr) with La0.5Sr0.5CoO3 bottom electrode (Pr ≈ 34 μC/cm2) after a drive voltage of 9 V was observed when compared with the same film deposited on Pt substrate. The leakage current behavior at room temperature decreased from 10−8 (Pt) to 10−10 A/cm2 on (La0.5Sr0.5CoO3) electrode under a voltage of 5 V. The fatigue resistance of the Au/BLFO015/LSCO/Pt/TiO2/SiO2/Si (1 0 0) capacitors with a thickness of 280 nm exhibited no degradation after 1 × 108 switching cycles at a frequency of 1 MHz.