Compositional dependence of properties of Pb(Yb1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 ternary ferroelectric crystals
Abstract
A series of Pb(Yb1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 ternary ferroelectric crystals with different compositions have been grown by the top-seeded solution growth technique in order to investigate systemically this ternary system based on the single crystal form. The compositional segregation and the compositional dependence of electric properties have been studied for the selected compositions in the vicinity of the morphotropic phase boundary (MPB) region. All the samples exhibit perovskite structure with rhombohedral symmetry at room temperature. The lattice parameter (a), coercive field Ec, Curie temperature TC, the rhombohedral–tetragonal phase transition temperature Trh–te increase gradually with increasing PYN content. All the samples exhibit quite high piezoelectric performance. In particular, the crystal with composition 0.20PYN–0.40PMN–0.40PT possesses excellent electric properties such as TC = 180 °C, Trh–te = 130 °C, k33 = 90.9%, d33 = 2240–2580 pC N−1, Pr = 28.4 μC cm−2 and Ec = 5.4 kV cm−1, indicating that the PYN–PMN–PT ternary crystals will be a promising candidate for electromechanical applications.