Improvement in the sintering process of Ba0.85Ca0.15Zr0.1Ti0.9O3 ceramics by the replacement of Zr by Hf

We investigate the effects of replacing Zr4+ ions by Hf4+ on the sintering and electrical properties of Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) lead-free piezoceramics. For that purpose, Ba0.85Ca0.15Hf0.1Ti0.9O3 ceramics were sintered at different temperatures and their properties were compared to those of BCZT fabricated under the same conditions. We show that Hf as B-site dopant facilitates the formation of the perovskite phase during the calcination process and improves the electrical properties of the ceramics due to the development of a denser microstructure with greater grain size and lower porosity.