To reveal the physical mechanism underlying the excellent electromechanical properties of the lead-free ferroelectric material Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 (BCZT), an eighth-order Landau-Devonshire thermodynamic potential function for BCZT single crystal was constructed. The model reproduces the paraelectric-tetragonal-orthogonal-rhombohedral phase transition sequence and its temperature dependence under zero-field conditions. The obtained phase boundary, polarization, dielectric, and piezoelectric properties are consistent with the experimental results. The evolution of the phase structure and changes in the electromechanical response under the action of the 001 electric field were further analyzed. An electric-field-temperature phase diagram was generated, and it was predicted that an electric field could induce the formation of monoclinic phases M A and M C and drive phase-boundary migration. The results show that the improvement in electromechanical response is due to the electric field changing the phase stability region and inducing polarization reconstruction. Near the field-induced phase transition boundary, especially in the paraelectric to tetragonal transition region, ε 33 and d 33 are significantly enhanced. This work provides a systematic thermodynamic theoretical foundation for understanding the electric-field-driven phase transition and performance evolution of BCZT. • BCZT phase transitions are well captured by an eighth-order Landau model. • Self-consistent parameters match experimental polarization and dielectric data. • Electric field induces monoclinic intermediate phases M A and M C . • A field-driven phase diagram shows migration of phase boundaries. • Enhanced d 33 and ε 33 correlated to polarization reconstruction.
Peng et al. (Thu,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: