Effect of oxygen octahedral tilt on ferroelectric-antiferroelectric transition of PZT95/5 induced by hydrostatic pressure and electric field: A phenomenological thermodynamic analysis

Ceramic PZT95/5 lies near the boundary between the ferroelectric and antiferroelectric phases and undergoes complex domain switching and various phase transitions in response to temperature, pressure, and electric fields. This phenomenon often leads to unusual performances, making it challenging to characterize and control the electromechanical properties of the material. In particular, the phase transition from ferroelectric rhombohedral to antiferroelectric orthorhombic is caused by the combined effect of polarization switching and oxygen octahedral tilt. However, the underlying mechanism of their interaction is still unclear, resulting in a lack of thermodynamic models for ferroelectric-antiferroelectrics in multifield settings. In this study, a thermodynamic model was established by considering the combined effect of oxygen octahedral tilt, polarization, and stress, which can describe the polarity characteristics of phase transitions in PZT95/5 under multiple fields. This model comprehensively accounts for all phases of PZT95/5 and successfully simulates the experimental phase diagram of PZT95/5 under hydrostatic pressure. The tilt angle of the oxygen octahedra and the polarization were incorporated to reveal the special polarity microstructure of the intermediate phase between the ferroelectric and antiferroelectric phases and determine the effect of pressure on the incommensurate modulations. Exploring the application of antiferroelectric materials in smart devices via the pressure-induced transition of incommensurate modulation phases may become a new possibility.