Compositional phase diagram design, synthesis process phase evolution route, and comprehensive performance comparison of BTWO-based ceramics with existing mainstream dielectric tunable materials.

A research team led by Professor Zhou Di from the School of Electronic Science and Engineering at Xi'an Jiaotong University (XJTU) has unraveled the origins of the exceptional performance in the non-perovskite structured Bi₆Ti₅WO₂₂ (BTWO) relaxor ferroelectric ceramic system. They resolved the precise crystal structure of this composition and elucidated the physical mechanism enabling the coexistence of high tunability and low loss.

The results show that at the optimal composition (BTWO-49Bi), the ceramic achieves high densification and phase purity. Statistical quantitative analysis combining Raman spectroscopy and full width at half maximum (FWHM) confirms that local lattice variations at this optimal composition are minimized.

This high degree of microstructural homogeneity endows intrinsic polar nanoregions (PNRs) with greater rotational freedom, allowing them to exhibit a highly cooperative response to external electric fields.

Under a driving electric field of 30 kV cm^-1, the material attains a dielectric tunability of ≈60 percent, while maintaining a dielectric loss (tan δ) on the order of ~ 10^-4, ultimately yielding an impressive figure of merit (FOM) of ≈1500. This study offers a valuable design strategy for improving dielectric performance by suppressing structural disorder in future developments.

The research findings were published in the internationally renowned academic journal Advanced Functional Materials (IF=19.9) under the title Breaking the Tunability–Loss Trade-off in Bi₆Ti₅WO₂₂-Based Relaxors via Nominal Compositional Tuning.