Elastic, piezoelectric, and dielectric properties of 0.955Pb(Zn/sub 1/3/Nb/sub 2/3/)O/sub 3/-0.45PbTiO/sub 3/ single crystal with designed multidomains

The elastic, piezoelectric, and dielectric properties of a 0.955Pb(Zn/sub 1/3/Nb/sub 2/3/)O/sub 3/-0.045PbTiO/sub 3/ (PZN-4.5%PT) multi-domain single crystal, poled along [001] of the original cubic direction, have been determined experimentally using combined resonance and ultrasonic methods. At room temperature, the PZN-4.5%PT single crystal has rhombohedral symmetry. After being poled along [001], four degenerate states still remain. Statistically, such a domain-engineered crystal may be treated as having an average tetragonal symmetry, and its material constants were determined based on 4 mm symmetry. It was confirmed that the electromechanical coupling coefficient k/sub 33/ for the domain-engineered samples is >90%, and the piezoelectric constant d/sub 33/ is >2000 pC/N. A soft shear mode with a velocity of 700 m/s was found in the [110] direction. From the measured experimental data, the orientational dependence of phase velocities and electromechanical coupling coefficients was calculated. The results showed that the transverse and longitudinal coupling coefficients, k/sub 31/ and k/sub 33/, reach their maximum along [110] and [001], respectively.