Movement of dislocations in quartz

When quartz is subjected to high stress and temperature, it flows (plastically deforms) through a mechanism involving the movement of dislocations. The author discusses historical background and current theories of dislocations in quartz. A review is given of the literature, including geophysical work, and its implications for frequency control. Dislocations in quartz crystals have been known to cause problems in the fabrication of resonators by the formation of etch channels. In addition, it is suspected they contribute to acceleration sensitivity, thermal hysteresis, and possibly aging. It has been shown in the geophysical work that dislocations definitely can move in quartz. However, all of that work was done at high temperatures and pressures.<>