Piezoelectric Resonance Properties of a β Phase Quartz Plate

We have previously reported an artificial twinning (x-axis inversion) technique for rotated Y-cut quartz plates. The twinning is produced by mechanical stress through a thin metal film deposited on the plate. Such a twinning phenomenon occurs at a considerably lower temperature than the α-β transition temperature, Tc, of 573°C. This paper presents the electromechanical properties of quartz at a temperature region higher than the twinning temperature. Degeneration of the piezoelectric resonances corresponding to the x-axis inversion area and the non-inversion area are observed at a temperature between the twinning temperature and Tc. The elastic stiffness constants c55 and c66, estimated from the degeneration mode resonance frequency, agree with these for the β phase. This suggests that the α-β transition occurs by the thin metal film at a considerably lower temperature than Tc of 573°C. An intense piezoelectric response with a high quality factor above 20,000 is observed from the degeneration temperature to above 660°C.