Synthesis and properties of La-doped PMN–PT transparent ferroelectric ceramics

Transparent ferroelectric ceramics 0.88Pb(Mg_1/3Nb_2/3)O₃–0.12PbTiO₃ (0.88PMN–0.12PT) with different La-doping concentrations (0.5, 1.0, 1.5 and 2.0 mol%) were fabricated via solid-state reaction and two-stage sintering. The effects of La-doping on the microstructure and electrical properties of the 0.88PMN–0.12PT ceramics were investigated. All the La-doped 0.88PMN–0.12PT ceramics exhibit pure perovskite phase with extremely dense microstructure and high optical transmittance. Among them, the 1.0 mol% La-doped ceramics show the highest transparency around 70% in near-infrared region, which is very close to its theoretical transmittance and basically meet the requirement on the transparency of electro-optical applications. The remanent polarization P_r, coercive field E_c, ε_max, the temperatures Tε_max corresponding to ε_max of the 0.88PMN–0.12PT ceramics decreased, and the relaxor behavior enhanced apparently with increasing La-doping concentration, which may ascribe to the fact that the substitution of Pb²⁺ ions by La³⁺ions reduces the long-range coupling of BO₆ octahedrons.