Electromechanical properties and domain evolution of a tetragonal Er3+-doped Pb(Mg1/3Nb2/3)O3–PbTiO3 ferroelectric single crystal

Abstract

Herein, a tetragonal Er3+-doped Pb(Mg1/3Nb2/3)O3–PbTiO3 single crystal is comprehensively investigated. The actual composition of the studied crystal is Pb(Mg1/3Nb2/3)O3–36PbTiO3 doped with 0.17-mol% Er3+ (PMN–36PT: 0.17-mol% Er3+). The crystal exhibits a high shear piezoelectric constant of ∼936 pC/N, approximately three times the longitudinal piezoelectric constant when poled along [001]c, as well as a higher Curie temperature of ∼170 °C and large coercive field of ∼4.58 kV/cm. At room temperature, the crystal presents a mass of domain walls along the <110>c direction and extinction is observed four times within a 360° rotation, showing typical domain features of the tetragonal phase. Under a direct current–electric field along the [010]c direction, the extinction rule remains unchanged; however, changes in the domain configuration can be observed. In addition, the orientation dependence of the piezoelectric constant, dielectric coefficient, elastic compliance constant, and electromechanical coupling factor is calculated using the coordinate transformation method. The findings of this study are of considerable importance for the fundamental studies and device design of tetragonal ferroelectric crystals.