Yang Chen, Xu Xijun, Ali Wajid, Wang Yaojin, Wang Yiping, Yang Ying, Chen Lang, Yuan Guoliang
School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Precision Driving Laboratory, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
ACS Appl Mater Interfaces. 2021 Jul 21;13(28):33253-33261. doi: 10.1021/acsami.1c07492. Epub 2021 Jul 6.
Ultrasonic sensors are widely applied in industries near room temperature; however, their application at high temperature is still a challenge mainly due to the lack of high-performance piezoelectric ceramics. Here, the 0.364BiScO-0.636PbTiO-0.005CaTiO ceramic exhibits excellent piezoelectric performances at 20-440 °C. Its piezoelectric coefficient increases from 475 pC/N at 20 °C to 853 pC/N at 360 °C, and then it gradually decreases to 669 pC/N at 440 °C. Furthermore, the planar electromechanical coupling factor gradually increases from 0.59 at 20 °C to 0.67 at 200 °C, and then it remains at a stable value of 0.65-0.67 at 150-350 °C. These achievements are because the ceramic morphotropic phase boundaries have a flat Gibbs free energy versus polarization curve and a wide temperature range. Since the piezoelectric ceramic shows satisfactory piezoelectric properties at 20-440 °C, the corresponding ultrasonic sensors can in situ monitor many high-temperature devices, such as engines, wheels, drills, boilers, etc.
超声传感器在接近室温的工业领域中得到了广泛应用；然而，由于缺乏高性能压电陶瓷，它们在高温下的应用仍然是一个挑战。在此，0.364BiScO-0.636PbTiO-0.005CaTiO陶瓷在20-440°C范围内表现出优异的压电性能。其压电系数从20°C时的475 pC/N增加到360°C时的853 pC/N，然后在440°C时逐渐降至669 pC/N。此外，平面机电耦合系数从20°C时的0.59逐渐增加到200°C时的0.67，然后在150-350°C范围内保持在0.65-0.67的稳定值。这些成果是因为该陶瓷准同型相界具有平坦的吉布斯自由能与极化曲线以及较宽的温度范围。由于该压电陶瓷在20-440°C范围内表现出令人满意的压电性能，相应的超声传感器可原位监测许多高温设备，如发动机、车轮、钻头、锅炉等。
