标题：Single crystal growth and temperature dependent behaviors of melilite type piezoelectric crystal Ca2Al2SiO7
作者：Jiang, Chao ;Long, Yong ;Yu, Fapeng ;Kong, Lingfeng ;Chen, Feifei ;Tian, Shiwei ;Qin, Lifeng ;Cheng, Xiufeng ;Zhao, Xian
作者机构：[Jiang, Chao ;Yu, Fapeng ;Kong, Lingfeng ;Chen, Feifei ;Tian, Shiwei ;Cheng, Xiufeng ;Zhao, Xian ] Institute of Crystal Materials, Shandong University 更多
来源：Journal of Crystal Growth
摘要：High temperature piezoelectric crystals are desired for sensing at elevated temperatures. In this work, a large size (2 in.) and low cost Ca2Al2SiO7(CAS) crystal was grown by using the Czochralski pulling method. Thermal expansion coefficients α11and α33were measured and found to be on the order of 5.70 × 10−6/°C and 10.12 × 10−6/°C, respectively. The electrical resistivities of the CAS crystal along the X- and Z-directions at 700 °C were found to be 3 × 107and 2 × 108Ω·cm, respectively. The electro-elastic constants were evaluated by using the impedance and pulse-echo methods, where the piezoelectric coefficients d14and d36were determined to be 6.7 and 2.8 pC/N at room temperature, respectively. Moreover, the temperature dependence of the electro-elastic properties of the CAS crystal was investigated. The variation of elastic compliances was found to be <6% over the tested temperature range of 20–700 °C. The optimum crystal cuts with the maximum longitudinal and thickness shear piezoelectric coefficients for the CAS crystal were predicted, where the largest longitudinal piezoelectric d11∗(3.1 pC/N) was achieved for the (XYtl)45°/−55° crystal cut, and the largest shear piezoelectric d26∗(4.7 pC/N) was found for the (YXl)45° crystal cut, nearly two times that of α-quartz.
© 2018 Elsevier B.V.