Design, fabrication, and characterization of high-temperature piezoelectric vibration sensor based on the Ho: CNGS crystal

Abstract

In this letter, a Ho3+: Ca3NbGa3Si2O14 (Ho: CNGS) piezoelectric crystal with high quality and large size (Φ 34 mm × 52 mm) was grown by the Czochralski method, and a compressive mode piezoelectric vibration sensor with longitudinal d11 mode was fabricated based on the good properties of Ho: CNGS. The resistivity at elevated temperatures of Ho: CNGS could be enhanced significantly by doping Ho3+, and the ρ11 was three orders of magnitude higher than La3Ga5SiO14 and one order of magnitude higher than Ca3NbGa3Si2O14. The low dielectric loss and stable electro-elastic properties at high temperatures were also presented, and the electro-elastic constants were effectively improved compared with the pure Ca3NbGa3Si2O14 crystal. The sensor exhibited a maximum sensitivity temperature deviation of less than 5.2% from room temperature to 600 °C under the excitation frequency of 80 ̶ 315 Hz.