Sintering densification driven by orientation fluctuation in textured BaTiO ₃ ceramics with abnormal comprehensive ferroelectric properties

A new sintering densification method without the aid of liquid-phase is proposed for preparing the [001]_c-textured BaTiO₃ ceramics with high ferroelectric performances. With the help of phase-field modeling, the size and concentration of templates is optimized to control the densification process. Compared with randomly oriented BaTiO₃ ceramics, the prepared textured BaTiO₃ ceramics with designed templates verify the improvement in crystallographic preferred orientation and densification by the orientation fluctuation of nucleation and growth that breaks the limitation of symmetry-constrain strains. Such a new densification mechanism is comprehensively revealed by the active energies of sintering curves and the electron backscattered diffraction analysis, where an obvious anisotropic shrinkage boosting the densification manifests a different driving force from that of the normal liquid-phase sintering method. The resulting highly textured BaTiO₃ ceramics exhibit abnormal comprehensive ferroelectric properties, achieving a high piezoelectric constant d₃₃ of 490 ± 11 pC·N^-1 that exceeds BaTiO₃ single crystals while having small remanent polarization (8.5 mC·cm^-2 at 15 kV·cm^-1). Thus, the current method is expected to provide a new strategy for preparing textured ferroelectric ceramics with high performance.