Preparation, structure, and electric properties of the Pb(Zn1/3Nb2/3)O3–Pb(Yb1/2Nb1/2)O3–PbTiO3 ternary ferroelectric system ceramics near the morphotropic phase boundary

Abstract

Ceramics of the x Pb(Zn 1/3 Nb 2/3 )O 3 –(1 − x − y )Pb(Yb 1/2 Nb 1/2 )O 3 – y PbTiO 3 (PZN–PYN–PT) ternary system were synthesized using a modified two-step columbite precursor method which can effectively suppress the pyrochlore phase. A morphotropic phase boundary (MPB) region, separating tetragonal and rhombohedral phases in the ternary systems has been determined. The electric properties of the compositions near MPB region were investigated. Dielectric response exhibits relaxor-like characteristics with broad dielectric peaks and dispersive dielectric behavior with respect to frequency and temperature. The phase diagram of the 0.45PZN–(0.55 − y )PYN– y PT pseudo-binary system in the composition range of 0.15 < y < 0.35 was established based on dielectric measurements. The optimal properties were achieved in the MPB composition of 0.52PZN–0.21PYN–0.27PT with piezoelectric coefficient d 33 , dielectric permittivity ε ′, planar electromechanical coupling k p , dielectric loss tan δ , coercive field E c , remnant polarization P r , and T C being of 558 pC/N, 2065, 62%, 0.2%, 19.88 kV/cm, 31.44 μC/cm 2 and 259.5 °C, respectively, showing potential usage in high-temperature electromechanical applications.