Sintering and enhanced ferroelectric properties of textured Bi5Ti3FeO15 ceramics with high Curie temperature

Abstract

We prepared highly textured Bi₅Ti₃FeO₁₅ (BTFO) ceramics with excellent ferroelectric properties using the template grain growth method (TGG). The sintering densification behavior and grain orientation evolution of highly anisotropic textured BTFO ceramics are analyzed by various characterization methods. The obtained textured BTFO ceramics exhibit increased remanent polarization within a slight temperature range from 25 °C to 60 °C due to the stress release in the a–b planes. The piezoelectric coefficient value d₃₃ of textured BTFO ceramics is 23.0 pC N⁻¹, which is about 3.7 times higher than that of the random ceramics. Compared to Bi₄Ti₃O₁₂ (677 °C), the increasing Curie temperature (767 °C) of BTFO is attributed to the larger distortion of TiO₆ octahedra, which is also confirmed by energy barriers in DFT calculations. The antiferromagnetic characteristics also provide feasibility for magnetoelectric coupling in BTFO materials.