Competition of Li+ and Cu2+ ions dopant in BiAlO3–Pb(Zr,Ti)O3 piezoelectric ceramics in low temperature sintering processes

Abstract

Sintering with sintering aids is widely used to achieve a low sintering temperature of lead-based piezoelectric ceramics. In this study, two low-temperature sintering aids, namely Li2CO3 and CuO, were doped into the x BiAlO3-(1-x) PZT + 0.2 wt% MnO2 composition, and the microstructures and electrical properties were investigated for these ceramics prepared via solid-phase reaction method. Differential Scanning Calorimetry (DSC) indicated that the Li2CO3 liquid phase formed at a lower temperature than that of CuO, while co-dopant of Li2CO3 and CuO will result in a competition between Li+ and Cu2+ ions during the low-temperature sintering processes, which negatively impacts piezoelectric properties. The results demonstrated that the piezoelectric properties of ceramics with only Li2CO3 or CuO additives are much better than ceramics with co-doped Li2CO3 and CuO additives. Ceramics with 0.3 wt% Li2CO3 or 0.1 wt% CuO sintering aid were sintered at 1000 °C, resulting in excellent piezoelectric coefficients (d33) exceeding 300 pC/N and mechanical quality factors (Qm) of 500 were obtained, respectively. This work provides inspiration for low-temperature sintering strategies in other ceramic materials.