Investigation of elastic nonlinearities in Pb(Zn1/3Nb2/3)O3-PbTiO3 and Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals

The complex elastic and electromechanical properties of Pb(Zn1/3Nb2/3)O-3-PbTiO3 (PZNT) and Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PMNT) single crystals under high power operational conditions have been determined using a new resonance method. In this method, rectangular specimens are piezoelectrically-driven into mechanical resonance and displacement of the transverse resonance mode is measured as a function of frequency (f) using an optical vibrometer method in conjunction with a frequency response analyzer. Under resonant high-power drive, it has been found that electromechanical nonlinearities are due to elastic ones, as the elastic and electromechanical properties were both found to scale with the square of the strain amplitude. The temperature (T) and ac electric field (E-ac) dependence of the mechanical quality factor Q(m) was also determined and Iso-Q(m) curves were constructed that can be used to predict performance criteria for high power applications.