High temperature piezoelectric properties and ultra-high temperature sensing properties of bismuth tungstate
Yaoyao Liao, Qingwei Liao, Yuxiang Yin, Yinghao Li, M. C. Du, Hanqing Zhao, Lingxia Li, Yuying Wang, Lei Qin
Abstract
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 Bi<sub>2</sub>Mo<sub><i>x</i></sub>W<sub>1−<i>x</i></sub>O<sub>6</sub> (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 <i>x</i> = 0.001, the ceramic sample has the best performance: the relative density of 92%, the piezoelectric coefficient (<i>d</i><sub>33</sub>) of 15 pC·N<sup>−1</sup>, the quality factor (<i>Q</i><sub>m</sub>) of 1642, the dielectric constant (<i>ε</i>) of 307 (1 kHz), and the dielectric loss (tan<i>δ</i>) of 0.33 (1 kHz). With increasing B-doped Mo<sup>6+</sup> 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<sup>−1</sup>. 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<sup>−1</sup><strong>;</strong> the linearity is greater than 0.99, and the sensitivity deviation is 1.4%.