Domain-refinement-induced large piezoelectricity in V-doped Bi₄Ti₃O₁₂ textured ceramics with compressive strain

Texture engineering represents an effective strategy to enhance the piezoelectric properties of ceramics. Nevertheless, the piezoelectric properties of Bi₄Ti₃O₁₂ textured ceramics have not yet reached the ideal level because their remnant polarization P_r remains lower than the theoretical prediction. Herein, a combined approach of texture engineering and doping with high-valence ions that have a small ionic radius was proposed to induce lattice compressive strain η₍₂₀₀₎ and effectively reduce the domain size in Bi₄Ti_3-xV_xO₁₂ ceramics. The Bi₄Ti_2.97V_0.03O₁₂ textured ceramics exhibited a large η₍₂₀₀₎ of 0.65 %, resulting in a piezoelectric coefficient d₃₃ of 42 pC/N. The smallest domain size was achieved in the Bi₄Ti_2.97V_0.03O₁₂ textured ceramics, with a length of 0.33 μm and a width of 0.17 μm, which is beneficial to polarization rotation thus improving the piezoelectric properties. Therefore, the reduction in domain size and the large lattice compressive strain were critical factors in enhancing the piezoelectric properties of Bi₄Ti_2.97V_0.03O₁₂ ceramics.