Enhanced ferroelectric properties of La-substituted BiFeO3 thin films on LaSrCoO3/Pt/TiO2/SiO2/Si (100) substrates prepared by the soft chemical method

Abstract Bi 0.85 La 0.15 FeO 3 (BLFO015) thin films were deposited by the polymeric precursor solution on La 0.5 Sr 0.5 CoO 3 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 ( P r ) with La 0.5 Sr 0.5 CoO 3 bottom electrode ( P r  ≈ 34 μC/cm 2 ) 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/cm 2 on (La 0.5 Sr 0.5 CoO 3 ) electrode under a voltage of 5 V. The fatigue resistance of the Au/BLFO015/LSCO/Pt/TiO 2 /SiO 2 /Si (1 0 0) capacitors with a thickness of 280 nm exhibited no degradation after 1 × 10 8 switching cycles at a frequency of 1 MHz.