Effects of a viscous and conductive liquid on thickness shear vibration of ZnO films with tilted c-axis orientation

The thickness-shear vibration of c-axis tilted 430 ZnO thin film, one side of it is contacted with a layer of viscous conductive liquids is analyzed. The frequency equation has been derived from the three-dimensional linear piezoelectricity theory. The effects of conductivity on the shift in the resonant frequency has been analyzed and discussed in detail. By setting the density, the viscous coefficient and the thickness of the liquid as specified values, the relation of the shift in the resonant frequency and the conductivity is obtained. The present results demonstrate that the shift in the resonant frequency decreases with the conductivity in a special range. Analysis method and calculation results can provide important reference to the resonators design.