Effects of the Sn⁴⁺ Substitution and the Sintering Additives on the Sintering Behavior and Electrical Properties of PLZT

Abstract

(Pb, La)(Zr, Ti)O3 (PLZT) with antiferroelectric properties can be applied as a capacitor whose capacitance increases in a high electric field. From this, we obtained a high sintering density at 950 °C by adding low-temperature sintering additives, 8.0 wt% of PbO and 2.5 wt% of ZnO, simultaneously to a (Pb0.88, La0.12)(Zr0.86, Ti0.14)O3 composition. The change in electrical characteristics was confirmed in terms of Sn4+ substitution, resulting in no change in the sintering density by Sn4+ substitution. However, as the amount of Sn4+ substitution increases, the dielectric constant gradually decreases from 1300 to 700, and the grain size decreases from about 4 to 1 µm in terms of microstructure. In the crystal structure analysis, the general formation of a single perovskite structure was confirmed. The results of the hysteresis curve measurement revealed that the breakdown electric field increases from 4 to 9 kV·mm−1 as the amount of Sn4+ substitution gradually increases. However, polarization decreases in the same way as the permittivity trend. The composition exhibits excellent electrical properties when the ratio of Sn4+ is 0.4: a high energy storage density of 3.5 J·cm−3, energy efficiency of 80%, and breakdown electric field of about 8.5 kV·mm−1.

Keywords

• antiferroelectric
• MLCC
• PLZST
• substitution
• additive