Large enhancement of energy-storage properties of compositional graded (Pb1−xLax)(Zr0.65Ti0.35)O3 relaxor ferroelectric thick films

In this letter, the compositionally graded multilayer (Pb1-xLax)(Zr0.65Ti0.35)O3 (PLZT) relaxor ferroelectric thick films were fabricated on LaNiO3/Si(100) substrates via a sol-gel method. The effects of composition-gradient sequence on the microstructure, dielectric properties, and energy-storage behaviors were investigated in detail. As compared to PLZT films with single composition, the compositionally graded PLZT films displayed significant enhancement in dielectric properties and energy-storage performance. The largest dielectric constant of 2170 at 100 kHz and the largest discharged energy-storage density of 12.4 J/cm3 at 800 kV/cm were achieved in the up-graded multilayer PLZT thick films.