Sintering densification driven by orientation fluctuation in textured BaTiO₃ ceramics with abnormal comprehensive ferroelectric properties

A new sintering densification method without the aid of a liquid phase is proposed for preparing [001]_c-textured BaTiO₃ ceramics with high ferroelectric performance. With the help of phase-field modeling, the size and concentration of the templates are optimized to control the densification process. Compared with randomly oriented BaTiO₃ ceramics, the prepared textured BaTiO₃ ceramics with designed templates demonstrate an improvement in the crystallographic preferred orientation and densification due to the orientation fluctuation of nucleation and growth, which overcomes the limitation of symmetric-constrain strains. This new densification mechanism is comprehensively revealed by the active energies of the sintering curves and electron backscattered diffraction analysis, where the obvious anisotropic shrinkage that increases 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, which exceeds that of BaTiO₃ single crystals while having small remanent polarization (8.5 μC·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.