Tuning the energy storage performance, piezoelectric strain and strain hysteresis of relaxor PLZT thin films through controlled microstructure by changing the ablation rate

Relaxor-ferroelectric Pb_0.9La_0.1(Zr_0.52Ti_0.48)O₃ (PLZT) films with a thickness of 1.2 μm were deposited on LaNiO₃-buffered Ca₂Nb₃O_10-nanosheet/Si. It was revealed how structural modification of a PLZT film, fabricated using pulsed laser deposition under various ablation rates, can be used to tune its energy-storage performance and piezoelectric-strain. A highest unipolar piezoelectric-strain of 0.71% with extremely low strain-hysteresis of 1.9% and corresponding normalized-strain of 142 pm/V under an electric field of 500 kV/cm were observed in the film deposited at an ablation rate of 50 Hz, and such film consists of vertical columnar-structure. Whereas, the film deposited at a low ablation rate of 10 Hz with dense-structure had the higher recoverable energy-storage density (50.2J/cm³) and energy-storage efficiency (82.2%) due to the larger electric-breakdown strength (3150 kV/cm). The strongly improved performance by choosing an appropriate film structure is important for practical applications in pulse-power energy-storage as well as for the development of piezo-driven microelectromechanical-systems.