Enhanced Dielectric and Ferroelectric Properties of Pb(Mg_1/3Nb_2/3)_0.65Ti_0.35O₃ Ceramics by ZnO Modification

Abstract

Phase formation, microstructures, dielectric, and ferroelectric properties of ZnO‐modified Pb(Mg1/3Nb2/3)0.65Ti0.35O3 (PMNT/xZnO, where x = 0, 0.4, 2.0, 4.0, and 11.0 mol%) ceramics were studied. A coexistence of rhombohedral and tetragonal ferroelectric phases was observed at room temperature in all samples. The ceramics with the relative densities of 93%–95% were prepared. The modification by ZnO led to an increase in grain sizes of PMNT ceramics. The maximum dielectric constant of the pure PMNT ceramic was increased with x = 0.4–4.0 mol% ZnO doping, with the highest value being observed in the 2.0 mol% sample. Both the temperature at which the transition between rhombohedral and tetragonal ferroelectric phases took place (TR‐T) and the Curie temperature of the ceramics tended to increase with increasing x. The ferroelectric properties were enhanced with increased remanent polarization and P(E) loop squareness in the compositions with x = 0.4–4.0 mol%. However, the ferroelectric properties were attenuated with x = 11.0 mol%.

Synthesis of 0.64Pb(Mg1/3Nb2/3)O3–0.36PbTiO3 ceramic near morphotropic phase boundary for high performance piezoelectric, ferroelectric and pyroelectric applications

“…Due to the relaxor nature of PMN, PMN-PT can be categorized as relaxor-based ferroelectric materials that display a broad dielectric dispersion around Curie temperature (T c ), as compared to normal ferroelectric ones, which are characterized by a sharp and narrow peak at T c [5,6]. PMN-PT with excellent dielectric, piezoelectric and ferroelectric properties showing room temperature composition dependence establishes it as a promising material for applications in multilayer capacitors, actuators, sensors, electro-optical and electronic devices [7,8].…”

“…The remnant polarization, varying between 10.60 and 34.06 C/cm 2 , shows increasing-decreasing pattern with temperature. The squareness factor of the loops was calculated by using empirical expression given as [7], R sq = P r P max + P 1.1Ec P r (4)…”