Temperature Characteristics of β-Phase Quartz Resonators and Their Application to Accurate Temperature Sensors in High-Temperature Region

摘要

Quartz has been widely used for resonators and filters because of its excellent electromechanical characteristics. Quartz has a transition temperature TC of 573 ℃. The electromechanical characteristics of quartz have been well investigated for the α-phase (below TC), but the characteristics in the β-phase have not been well clarified. We investigated the piezoelectric properties of P-quartz plates from 573 ℃ to about 1,300 ℃. Clear piezoelectric resonances with high quality factors were observed. By using the large frequency temperature coefficient, β-phase quartz can be applied to temperature sensors in the high-temperature region above 600 ℃. We also propose an unwired setup using the Pphase quartz temperature sensor.