Ferroelectric and nano-mechanical properties of the chemical solution deposited lead-free BCZT films

Abstract Lead-free ferroelectric BCZT ((Ba0.85Ca0.15)(Ti0.9Zr0.1)O3) films with thickness ~ 750 nm were deposited on Si/SiO2/TiO2/Pt (1 0 0) substrates using polyvinyl pyrrolidone modified chemical solution. BCZT films crystallized at 800 °C showed better electrical and mechanical properties as compared to the films crystallized at 700 °C. The BCZT films crystallized at 800 °C exhibited maximum polarization of 58 µC/cm2 and energy storage density of 27.53 J/cm3. Furthermore, these films displayed extremely low dielectric loss and leakage current densities. The dielectric loss varied from 0.005 to 0.026 in measured frequency range: 3 kHz to 500 kHz. Hardness and elastic modulus values calculated from nanoindentaion measurements of the 700 °C annealed film were 5.2 ± 0.3 GPa and 87.3 ± 2.6 GPa respectively. The same for the 800 °C annealed film were 3.9 ± 1.02 GPa and 227 ± 28 GPa respectively. The higher values of elastic modulus of the 800 °C annealed film could be correlated to the microstructure of the film.