Growth of Pb(Fe1/2Nb1/2)O3–Pb(Yb1/2Nb1/2)O3–PbTiO3 piezo-/ferroelectric crystals for high power and high temperature applications

Abstract

In order to develop new piezoelectric crystals with high T_C and high performance for high-power and high-temperature applications, the Pb(Fe_1/2Nb_1/2)O₃–Pb(Yb_1/2Nb_1/2)O₃–PbTiO₃ [PFN–PYN–PT(10/38/52)] ternary piezo-/ferroelectric single crystals have been grown by the flux method for the first time. The crystal structure has been characterized by means of X-ray diffraction technique, showing a perovskite phase with rhombohedral symmetry at room temperature. The as-grown PFN–PYN–PT crystal possesses a high Curie temperature (T_C) of 325 °C and a high rhombohedral-tetragonal phase transition temperature (T_rt) of 155 °C. Complete electric characterization has revealed the high performance of the ternary crystals, with a dielectric constant ε′ = 1620, a piezoelectric coefficient d₃₃ = 1100 pC N⁻¹, a longitudinal electromechanical coupling factor k₃₃ = 70%, a remnant polarization P_r = 25.8 μC cm⁻², a coercive field E_c = 10.3 kV cm⁻¹, and a mechanical quality factor Q_m = 110 for (001)-oriented crystals at room temperature. These results show that the PFN–PYN–PT crystals are a promising candidate for uses in electromechanical transducers for high-power and high-temperature applications.