Acoustic and electrical properties of Ca3TaGa3Si2O14 piezoelectric resonators at elevated temperatures

Published

November 3, 2013

Author(s)

Ward L. Johnson, Michal Schulz, Holger Fritze

Abstract

Synthetic piezoelectric crystals in the P321 crystal class have been a focus of substantial research in relation to their application in high-temperature resonant bulk-acoustic-wave (BAW) and surface-acoustic-wave (SAW) sensors. Most of this research has been on partially disordered langasite (LGS) and langatate (LGT), but fully ordered crystals in this class, such as Ca3TaGa3Si2O14 (CTGS), have been suggested as offering potentially superior performance. In this study, acoustic characteristics and electrical conductivity of CTGS bulk acoustic resonators with a crystal orientation of (YXl) -30° are investigated at the fundamental mode of 5 MHz and overtones of 15 MHz and 25 MHz in the temperature range from room temperature to 1100 °C. Magnitudes of the temperature derivatives of the frequencies are found to be less than 41 ppm/K over this range, with turnover temperatures near 200 °C for the third and fifth overtones. The acoustic loss 1/Q at ambient temperatures is found to be higher than the lowest values previously reported for LGS and LGT. Between 100 °C and 700 °C, 1/Q has two anelastic relaxation peaks that are similar to those previously reported for LGS and LGT. The electrical conductivity over the range from 500°C to 1100 °C is found to be approximately an order of magnitude lower than that previously reported for LGS, and this leads to a reduction in 1/Q at elevated temperatures.

Proceedings Title

2013 IEEE Sensors

Conference Dates

November 4-6, 2013

Conference Location

Baltimore, MD

Pub Type

Conferences

Download Paper

https://doi.org/10.1109/ICSENS.2013.6688573

Keywords

acoustic resonators, BAW resonators, Ca3TaGa3Si2O14, CTGS, conductivity, high temperature, langasite, piezoelectric materials

Citation

Johnson, W. , Schulz, M. and Fritze, H. (2013), Acoustic and electrical properties of Ca3TaGa3Si2O14 piezoelectric resonators at elevated temperatures, 2013 IEEE Sensors, Baltimore, MD, [online], https://doi.org/10.1109/ICSENS.2013.6688573 (Accessed December 13, 2024)