The demand for ultra-high-temperature piezoelectric sensors in industrial applications has witnessed a rapid upsurge. In this study, the piezoelectric properties of La₂Ti₂O₇ (LTO) piezoelectric ceramics with a perovskite-like layered structure were enhanced by doping with Li/Ce ions. It was found that a remarkable 300% enhancement in the piezoelectric constant (d₃₃) value was achieved in Li/Ce-doped LTO ceramics compared to their pristine counterparts, reaching 6.4 pC N⁻¹ at room temperature with an ultra-high Curie temperature of 1408 °C. After annealing at 500 °C, the d₃₃ value of the samples can be further improved to 7.4 pC N⁻¹. Moreover, temperature-dependent resistivity measurements indicate that even at 1000 °C, the ceramics exhibit a high resistivity of 8.9 × 10⁵ Ω cm. By combining X-ray diffraction, Raman spectra, transmission electron microscopy and piezoresponse force microscopy data, the enhanced piezoelectricity of the ceramics is attributed to local heterogeneity induced by Li/Ce doping. Our results unequivocally demonstrate the suitability of modified LTO ceramics for ultra-high-temperature piezoelectric applications.

中文翻译：

---

Li/Ce掺杂La2Ti2O7陶瓷的超高压电性能和超高居里温度

工业应用对超高温压电传感器的需求迅速增长。在本研究中，通过掺杂Li/Ce离子增强了具有类钙钛矿层状结构的La ₂ Ti ₂ O ₇ (LTO)压电陶瓷的压电性能。研究发现，与原始陶瓷相比，Li/Ce 掺杂的 LTO 陶瓷的压电常数 ( d _{33 ) 值显着提高了 300%，在室温下达到 6.4 pC N} ^-1并具有超高居里温度1408℃。经过500℃退火后，样品的d _{33值可进一步提高至7.4 pC N} ^-1。此外，与温度相关的电阻率测量表明，即使在 1000 °C 下，陶瓷也表现出 8.9 × 10 ⁵ Ω cm 的高电阻率。结合X射线衍射、拉曼光谱、透射电子显微镜和压响应力显微镜数据，陶瓷的压电性增强归因于Li/Ce掺杂引起的局部异质性。我们的结果明确证明了改性 LTO 陶瓷适用于超高温压电应用。