Low temperature reactive sintering of CuO-doped PIN-PMN-PT ceramics

The effects of CuO-doping on perovskite phase formation and reactive sintering of 28Pb(In_1/2Nb_1/2)O₃-40Pb(Mg_1/3Nb_2/3)O₃-32PbTiO₃ ceramics were investigated, and the densification kinetics were compared with conventionally sintered ceramics. CuO-doping was observed by in situ x-ray diffraction to accelerate perovskite and suppress pyrochlore formation. 0.5 mol% CuO-doped PIN-PMN-PT ceramics sintered to ≥ 95% density as low as 790 °C. Comparable densification kinetics were observed with both conventional and reactive sintering. In the final stage of sintering, reactive sintering reduced the activation energy from 616 kJ/mol to 382 kJ/mol due to formation of a uniform 26–33 nm crystallite size microstructure that formed in situ at the onset of densification. Annealed reactively sintered ceramics also demonstrated equivalent ferroelectric behavior to conventionally sintered ceramics. We believe this work demonstrates a means to minimize material volatility during ceramic processing, an avenue for exploring co-firing with electrodes, as well as improved manufacturability through elimination of the perovskite powder synthesis step.