Variation of the piezo-electric constants of α-quartz with temperature

Abstract

The method of finding the piezo-electric constants with the help of the variations of bond distances and bond angles on strain has been utilised in finding the variations of the piezo-electric constants ε₁₁ and ε₄₁ of α-quartz with temperature. It is found that the variations of ε₁₁ with temperature can be explained on the basis of the change of co-ordinates with temperature. At 558° C. the silicon atoms are found to occupy the same positions as they do in β-quartz. As the transition temperature is reached, the longitudinal coefficient ε₁₁ drops to zero, while the transverse coefficient ε₄₁ decreases by only 15%. The piezo-electric constant of β-quartz has been similarly determined and its value comes out to be 1·05×10⁴ for a non-ionic crystal (k=·724) and 1·45×10⁴ for an ionic crystal (k=1).