Structure-piezoelectric property relationships in α-quartz isotypes: design and characterization of high performance piezoelectric materials

Structure-property relationships established for α-quartz isotypes indicate that the materials with the most distorted structures exhibit both the highest piezoelectric coupling coefficients and the highest thermal stability. It is found that thermal disorder results in a loss of piezoelectric properties, most noticeably a significant reduction in the Q-factor, particularly in the case of the least distorted materials such as a-quartz itself and this at temperatures well below the α-β phase transition. The most promising materials are predicted to be GeO₂ and GaAsO₄. These predictions are confirmed by piezoelectric measurements on Y-cut plates of GaAsO₄, which yield a piezoelectric coupling constant of about 20%, which is more than twice that of α-quartz.