Prediction of characteristic temperature of multicomponent ferroelectrics based on Landau–Devonshire model

Abstract The characteristic temperature, including the Curie temperature ( T c ${T}_{\mathrm{c}}$ ) and dielectric constant maximum temperature ( T m ${T}_{\mathrm{m}}$ ), plays a critical role in determining the operational temperature range and the inherent performance at room temperature for both the ferroelectric and relaxor ferroelectric materials. However, theoretical frameworks for predictingT c ${T}_{\mathrm{c}}$ andT m ${T}_{\mathrm{m}}$ in multicomponent ferroelectrics are limited. A linear model based on empirical observations exists, but it does not consistently yield accurate results, particularly for multicomponent ferroelectric systems. In this study, we developed a Landau–Devonshire (LD) model, which is based on the LD free‐energy theory, to accurately predict theT m ${T}_{\mathrm{m}}$ of multicomponent ferroelectrics. To evaluate the accuracy and generalizability of the LD model, we designed two series of ternary solid‐solution ceramics to act as the training and test sets, respectively. Our results demonstrated that theT m ${T}_{\mathrm{m}}$ predicted by the LD model was in close agreement with the experimental measurements, with a discrepancy as small as a few degrees. In addition, we observed that the LD model could be simplified to a linear model under specific conditions. Our study demonstrates that the LD model can provide theoretical guidance for designing multicomponent ferroelectrics with a specifiedT m ${T}_{\mathrm{m}}$ .