Tunable ferroelectric properties in (K 0.5 Na 0.5 )NbO 3 ceramics fabricated by a simple modification of the conventional sintering technique

Abstract

In this work, a modified sintering method, i.e. the three-step sintering technology, has been applied to fabricate the K_0.5Na_0.5NbO₃ ceramics. The impact of the detailed sintering conditions on the sinterability, dielectric and ferroelectric properties of K_0.5Na_0.5NbO₃ is systematically investigated. Attributed to the three-step sintering, the highest density of 4.07 g cm⁻³ can be observed, which is strongly improved compared with that of the single-step sintering technique and is increased up to 90% of the theoretical density. Furthermore, through the analysis on the tunability of the dielectric and ferroelectric performances, it is found that the maxima of permittivity and polarisation can be obtained in K_0.5Na_0.5NbO₃ sintering at 1160–1220–1120°C. These results illustrate that both the dielectric and ferroelectric behaviours can be effectively modulated through the simple modification of sintering technique, which would provide a novel route to achieve tunable electrical properties in ferroelectrics.