Structural disorder and loss of piezoelectric properties in α-quartz at high temperature

The piezoelectric properties of α-quartz-based resonators, characterized by the mechanical quality factor, Q, are found to degrade beginning above 300°C. This is well below the transition at 573°C to the β phase, which in principle limits the piezoelectric response of this material. This gradual loss of piezoelectric response can be linked to the increase in structural disorder in α-quartz found in total neutron scattering measurements. Analysis of these data by reverse Monte Carlo modeling indicates that between 200 and 400°C, the local disorder in the instantaneous structure of α-quartz becomes comparable to that of β-quartz.