Preparation and Properties of Pb(Sc_1/2Nb_1/2)O₃–Pb_0.85La_0.15Ti_0.96O₃ (PSN-PLT) Solid-Solution Ceramics

Pb(Sc_1/2Nb_1/2)O₃–Pb_0.85La_0.15Ti_0.96O₃ (PSN-PLT) solid-solution ceramics were prepared by the hot isostatic pressing (HIP) method in order to improve their porosity. Before sintering by the HIP, the two step calcining and ordinary sintering at around 1275° C for PSN and 1290° C for PSN-PLT were carried out. The highest density of 7.90 g/cm³ for PSN-PLT ceramics with 40 mol% PLT was obtained, which is in the range of 99.5% of the theoretical value. The maximum electromechanical coupling factors k _p of 0.68 and k _t of 0.55 were obtained in this PSN-PLT system close to the MPB composition. The dielectric constant of HIP PSN-PLT ceramics with the 40 mol% PLT was 5300 at room temperature, which is higher than that of the Pb(Sc_1/2Nb_1/2)O₃–PbTiO₃ (PSN-PT) system. Physical and electrical properties of one of the end members PSN and PLT, relaxor ferroelectric PSN, are also investigated.