The remarkable orientation and concentration dependences of the electromechanical properties of 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 single crystals

The present paper is devoted to evaluations of electromechanical constants of single-domain and multidomain relaxor-ferroelectric 0.67Pb(Mg1/3Nb2/3)O3- 0.33PbTiO3 single crystals near the morphotropic phase boundary. For the rhombohedral single crystal (3m class), piezoelectric coefficients and electromechanical coupling factors are calculated as functions of Euler angles. Features of orientation dependences of the piezoelectric coefficients and electromechanical coupling factors are first formulated and analysed. Two variants of concentration dependences of effective piezoelectric strain coefficients and electromechanical coupling factors are also first calculated, and the features of the piezoelectric activity of multidomain 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 single crystals are discussed