Enhanced electrical properties in textured Bi₄Ti₃O₁₂ ceramics with negative strain

In this work, we elucidated the reasons behind the superior electrical properties of Bi₄Ti₃O₁₂ (BTO) textured ceramics compared to BTO non-textured ceramics from the perspective of lattice strain. The phase structure, domain structure, and electrical properties of BTO textured and non-textured ceramics were analyzed in detail. The calculated average lattice strain along the polarization axis of textured ceramics with optimized processing was −0.27 %, while that of non-textured ceramics was 0.24 %. Compared to non-textured ceramics, the remnant polarization P_r of textured ceramics increased by 1.5 times, reaching 16 μC/cm². In addition, the piezoelectric constant d₃₃ was enhanced two times with a value of 19 pC/N. Notably, d₃₃ increased with an increase in average compressive strain along the polarization axis, indicating the enhancement of piezoelectricity caused by compressive lattice strain in the textured ceramics. The variation in d₃₃ was below 11.5 % in the heat-treatment temperature range of 25 °C–600 °C, demonstrating thermal stability in high-temperature service environments.