Temperature and electric-field induced phase transitions, and full tensor properties of [011]C-poled domain-engineered tetragonal 0.63Pb(Mg1/3Nb2/3)-0.37PbTiO3 single crystals

The phase-transition sequence of 0.67Pb(Mg1/3Nb2/3)-0.37PbTiO(3) (PMN-0.37PT) single crystals driven by the electric (E) field and temperature is comprehensively studied. Based on the strain-E field loop, polarization-E field loop, and the evolution of domain configurations, the E field along the [011](C) induced phase transitions have been confirmed to be as follows: tetragonal (T) -> monoclinic (M-C) -> single domain orthorhombic (O) phase. As the E field decreases, the induced O phase cannot be maintained and transformed to the M-C phase, then to the coexistence state of M-C and T phases. In addition, the complete sets of dielectric, piezoelectric, and elastic constants for the [011](C)-poled domain-engineered PMN-0.37PT single crystal were measured at room temperature, which show high longitudinal dielectric, piezoelectric, and electromechanical properties (epsilon(T)(33) = 10 661, d(33) = 1052 pC/N, and k(33) = 0.766). Our results revealed that the M-C phase plays an important role in the high electromechanical properties of this domain-engineered single crystal. The temperature dependence of the domain configuration revealed that the volume fraction of the M-C phase decreases with temperature accompanied by the reduction of epsilon(T)(33), d(31), and k(31) due to the substantially smaller intrinsic properties of the T phase.