Ba1-xCaxTi0.90Zr0·10O3 shear properties and their frequency dependence determined from ceramic plates by an effective method for resonance decoupling

Thickness poled, monomodal shear plate resonators were used for determination of shear coefficients of piezoelectric Ba1−xCaxTi0.90Zr0·10O3 ceramics with x = 0.10–0.18. The analysis of the impedance at resonance to obtain the coefficients was made by an iterative automatic method. All ceramics have d15 values close to d33 ones, meaning that they have mixed characteristics of extender and rotator ferroelectrics. We are able to effectively produce periodically decoupled fundamental shear modes in the thickness poled plate. We demonstrate this procedure for x = 0.15 ceramics and use it for the frequency dependence study of the properties determined from fundamental shear modes. The material stiffens up, is less piezoelectric and has higher losses as the frequency increases. This is due to the high contribution of the reversible domain wall motion to the piezoelectric activity in BCZT and the lower mobility, and higher internal friction, of the ferroelectric-ferroelastic domains as the frequency increases.