Difference between dynamic and hydrostatic pressure-induced phase transition behaviors of ferroelectric ceramics

PZT95/5 is a widely used ferroelectric material renowned for its exceptional ferroelectric properties, making it a crucial component in pulsed power systems and advanced devices. The phase transition behavior of ferroelectric ceramics under compression is vital for the effective design of materials and devices. The phase transition processes in these ceramics differ significantly between static and dynamic compression, presenting a long-standing controversy in the field. This study investigates the phase transition of PZT95/5 under dynamic shock compression using a shock response model. The findings indicate that the dynamic phase transition begins at lower pressures and completes at higher pressures compared to hydrostatic conditions, resulting in a broader pressure range for the phase transition. Theoretical modeling, grounded in ferroelectric and piezoelectric effects, combined with one-dimensional uniaxial stress density functional theory calculations across various orientations and three-dimensional Python visualizations, clarifies the physical mechanisms driving the progressive phase transition of ceramics under dynamic conditions. Additionally, the dynamic phase transition ratio of the ferroelectric material is quantified. Under hydrostatic pressures, the phase transition is independent of grain orientation, resulting in consistent transition pressures across all directions. In contrast, under anisotropic stress, grains with different orientations exhibit varying sensitivity to pressures, leading to distinct transition pressures in each direction. These insights advance the understanding of the phase transition mechanisms governing ferroelectric ceramics under both static and dynamic pressures.