Tunable ferroelectric properties in (K0.5Na0.5)NbO3 ceramics fabricated by a simple modification of the conventional sintering technique

In this work, a modified sintering method, i.e. the three-step sintering technology, has been applied to fabricate the K0.5Na0.5NbO3 ceramics. The impact of the detailed sintering conditions on the sinterability, dielectric and ferroelectric properties of K0.5Na0.5NbO3 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 K0.5Na0.5NbO3 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.