Rapid pressureless sintering of barium titanate–based piezoceramics and their electromechanical harvesting performance

Abstract

AbstractThe innovative method of processing of Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT), Ba0.95Ca0.05Ti0.91Sn0.09O3 (BCST), and BCZT doped with 0.07‐wt.% CeO2 (Ce‐BCZT) lead‐free piezoceramics is presented. The rapid pressureless sintering (RPLS) technique can reduce high‐temperature processing time more than eight times compared to the conventional sintering. RPLS was performed at a heating and cooling rate of 100°C/min up to 1550°C with 15‐, 30‐, 45‐, and 60‐min dwell times, producing defect and crack‐free nearly dense ceramics. The optimal microstructure exhibiting the highest piezoelectric constant was reached after 30 min in BCZT (grain size 25–30 μm, d33 = 428 pC/N), 45 min in Ce‐BCZT (grain size 30–35 μm, d33 = 515 pC/N), and 45 min of dwell time in BCST (grain size 58–68 μm, d33 = 443 pC/N). The highly competitive energy‐harvesting properties were discovered for BCZT, resp. Ce‐BCZT (ƞ = 94.5, resp. 93.4%, FOMoff = 6.1, resp. 7.8 × 10−10 m2/N) ceramics.