High-temperature piezoelectric single crystal ReCa4O(BO3)3 for sensor applications

摘要

Large-size and high-quality ReCa4O(BO3)3 (ReCOB, Re = rare earth) single crystals were grown by the Czochralski pulling method. In this work, the electrical properties were investigated at room temperature and elevated temperature for YCa4O(BO3)3 (YCOB). The dielectric permittivity, piezoelectric strain coefficient, and electromechanical coupling were found to be on the order of 11, 6.5 pC/N, and 12.5%, respectively, with a high piezoelectric voltage coefficient around 0.067 Vm/N. The electrical resistivity of YCOB was found to be 2 times 108 Ohmmiddotcm at 800degC, with Q values of > 4,500 at 950degC. The frequency/temperature coefficient of YCOB was found to be -75 to -85ppm/K in the temperature range of 30 to 950degC, depending on the crystal orientations. Together with their temperature-independent properties, ReCOB crystals are promising candidates for sensing applications at elevated temperatures.