Stress dependence of the electromechanical properties of ⟨001⟩-oriented Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals:: Performance advantages and limitations

The electromechanical properties of 0.7Pb(Mg1/3Nb2/3)O-3-0.3PbTiO(3) < 001 > -oriented crystals have been investigated under unaxial stress (sigma). The results demonstrate enhanced piezoelectric coefficients and electroacoustic power densities with increasing sigma. However, these increases are accompanied by significant increases in hysteretic losses. The results also demonstrate that the electromechanical coupling coefficient (similar to0.92) is relatively independent of sigma between 0 and 6x10(7) N/m(2). Future transducer designs can rely on piezocrystals offering a k(33) of 0.92, 10 dB more power, and low losses under operational conditions of sigma < 10(7) N/m(2) and 5 <T < 40 degreesC. (C) 2001 American Institute of Physics.