High temperature piezoelectric properties and ultra-high temperature sensing properties of bismuth tungstate

In energy generation, aerospace, and other related industries, high-temperature acceleration sensing is an essential tool for diagnostic testing, troubleshooting, and quality control. Currently, commercial acceleration sensors have a maximum operating temperature of no more than 550 °C. The study of high-temperature piezoelectric ceramics is important for increasing the operating temperature of sensors. In this work, high-temperature Bi₂Mo_xW_1−xO₆ (BW) piezoelectric ceramics were prepared, and an all-mechanical center compression high-temperature acceleration sensor was designed and fabricated. The results show that when the doping ratio is x = 0.001, the ceramic sample has the best performance: the relative density of 92%, the piezoelectric coefficient (d₃₃) of 15 pC·N⁻¹, the quality factor (Q_m) of 1642, the dielectric constant (ε) of 307 (1 kHz), and the dielectric loss (tanδ) of 0.33 (1 kHz). With increasing B-doped Mo⁶⁺ content, the Curie temperatures of the ceramics are 975, 966, 961, and 967 °C, and the high-temperature annealing temperatures are 975, 975, 950, and 950 °C, respectively. According to tests of temperature performance, the developed BW high-temperature sensor has a good linear response and sensitivity. At room temperature, a BW high-temperature piezoelectric sensor can be used stably within 1 kHz, and the average sensitivity is 3.259 pC·g⁻¹. At 800 °C, this device can be used in the frequency range of 0.1–1.1 kHz, and the average sensitivity is 3.305 pC·g⁻¹; the linearity is greater than 0.99, and the sensitivity deviation is 1.4%.