Ferroelectric and piezoelectric properties of Ba0.85Ca0.15Ti0.90Zr0.10O3 films in 200 nm thickness range

Lead-free piezoelectric Ba0.85Ca0.15Ti0.90Zr0.10O3 (BCZT) thin films were fabricated on Si/SiO2/TiO2/Pt (100) substrates following chemical solution deposition technique. Microstructure of the nano-sized BCZT particles crystallized in the thin film was thoroughly characterized. Ferroelectric, dielectric and piezoelectric properties of the films were investigated in detail. The BCZT films annealed at 800 degrees C temperature exhibited high remanent polarization of 25 +/- 1 C/cm(2), energy density of 17 J/cm(3), dielectric constant of 1550 +/- 50 and dielectric tunability of 50%. Converse piezoelectric coefficients (d(33)) obtained from piezo-response force microscopy (PFM) measurements on BCZT grains of different grain size (20-100 nm) distributed on the BCZT 700 film varied widely from 90 to 230 pm/V. The same for BCZT 800 measured on different grain size (30-130 nm) varied from 120 to 295 pm/V. These BCZT thin films with high dielectric, ferroelectric, and piezoelectric properties might be good alternative to the PZT films for thin film piezoelectric device applications

Superior energy storage performance and fatigue resistance in ferroelectric BCZT thin films grown in an oxygen-rich atmosphere

Ferroelectric properties of chemical-solution-deposited Ba0.85Ca0.15Ti0.90Zr0.10O3 (BCZT) thin films in the 200 nm thickness range, grown in air and oxygen-rich atmospheres, were investigated. Oxygen-processed BCZT thin films were found to have very slim hysteresis with higher polarization, lower remanent polarization (P-r), much lower coercivity and much higher dielectric breakdown strength. Those properties resulted in superior energy storage properties. Oxygen-processed BCZT thin films showed an energy storage density (ESD) of 64.8 J cm(-3) and energy storage efficiency (ESF) of 73% at 2000 kV cm(-1) electric field. Apart from that, the films showed very low leakage current and improved polarization fatigue properties. Oxygen-processed virgin BCZT film displayed maximum polarization (P-max) of 106 mu C cm(-2) and P-r of 12.9 mu C cm(-2), whereas the measured P-max and P-r of the fatigued film after 10(10) switching cycles were 105 mu C cm(-2) and 13.2 mu C cm(-2) respectively. BCZT thin films with high ESD and ESF at 2000 kV cm(-1) electric field and with excellent fatigue properties could be considered as potential candidates for low and intermediate voltage ferroelectric energy storage applications