(W1/3Cr2/3)4 + doping effects on the structural and electrical properties of Na0.5Bi4.5Ti4O15-based piezoceramics

Abstract

The Na_0.5Bi_4.5Ti₄O₁₅ (NBT) piezoelectric ceramic with a high Curie temperature (T_C) of 650°C, is a critical material for high-temperature sensors and actuators. Enhancing its piezoelectric coefficient (d₃₃) is crucial for expanding its application potential. Here, we propose a strategy to increase d₃₃ by substituting B-site Ti⁴⁺ with (W_1/3Cr_2/3)⁴⁺ to induce lattice distortion and regulate domain morphology, enhancing both intrinsic and extrinsic contributions. This system has achieved the highest reported d₃₃ value of 34 pC/N for NBT-based ceramics to date, along with a high T_C of 645°C and a resistivity as high as 10⁷ Ω·cm at 500°C. The enhanced piezoelectric performance arises from increased rotation angles of TiO₆ octahedra and changes in domain morphology. This study not only offers a high-performance material for applications in high-temperature devices operating at 500°C but also provides valuable insights into the enhancement and modification of piezoelectric properties in bismuth-layer-structured ceramics.