Orientation relationships between electromechanical properties of monoclinic 0.91Pb(Zn1/3Nb2/3)O3-0.09PbTiO3 single crystals

The relaxor-based ferroelectric 0.91Pb(Zn1/3Nb2/3)O3-0.09PbTiO3 single crystal provides remarkable piezoelectric and dielectric properties in the monoclinic phase near the morphotropic phase boundary that is important for various actuator and sensor applications. This paper first describes orientation dependencies of piezoelectric coefficients d3j and g3j (j = 1, 2, 3) and dielectric permittivity ε33T which have been calculated and analyzed for the single-domain monoclinic crystal sample. Results from calculations of these parameters at arbitrary orientations of the single-domain sample have been first systematized on the basis of a group of criteria and compared with known experimental data. The criteria introduced in this work enable to give the clear description of periodical and other changes in the piezoelectric and dielectric properties of the low-symmetry single-domain sample in terms of Euler angles. Some features of the dielectric anisotropy and high piezoelectric activity in the single-domain state have been considered. It has been shown that the dielectric anisotropy influences the piezoelectric sensitivity of the studied single crystal at various orientations.