Experimental study of thickness-shear vibration of AT-cut quartz resonators loaded with microparticles

We study experimentally thickness-shear (TSh) vibrations of an AT-cut quartz resonator loaded with a thin layer of microparticles. The effects of the particles on TSh resonant frequencies are examined. The inertia of the particles lowers the frequencies as expected. However, the frequency shift is found to be dependent on the particle size, and it may also be nonlinear in the particle layer thickness.