Stress dependence of the electromechanical properties of < 001 >-oriented Pb(Mg1/3Nb2/3)O-3-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). T he results demonstrate enhanced piezoelectric coefficients and electroacous tic power densities with increasing sigma. However, these increases are acc ompanied by significant increases in hysteretic losses. The results also de monstrate that the electromechanical coupling coefficient (similar to0.92) is relatively independent of sigma between 0 and 6x10(7) N/m(2). Future tra nsducer designs can rely on piezocrystals offering a k(33) of 0.92, 10 dB m ore 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.