DC bias dependence of piezoelectric properties of <111> oriented Pb(Zn/sub 1/3/Nb/sub 2/3/)O/sub 3/-PbTiO/sub 3/ single crystals

The piezoelectric d coefficients of <111> oriented (1-x)Pb(Zn/sub 1/3/Nb/sub 2/3/)O/sub 3/-xPbTiO/sub 3/ single crystals for x = 0.045 and x = 0.08 (PZN-4.5%PT and PZN-8%PT) have been measured as functions of DC bias field and frequency using a Zygo laser interferometer system. The d coefficients decreased as the DC bias was increased, perhaps because of domain wall clamping due to the bias field. The d coefficients were also found to decrease with the increase of frequency; this frequency dependence decreased at sufficiently large bias fields. High d/sub 15/ values (/spl sim/2800 pC/N for PZN-4.5%PT and /spl sim/3300 pC/N for PZN-8%PT) were measured, which may make these <111> oriented crystals promising candidates for high performance shear transducers.