Transparent high-performance piezoceramics through pressureless sintering

Piezoelectricity offers an electromechanical coupling that is widely utilized in transducer applications. There has been a consistent demand for transparent piezoelectric materials for optoelectrical applications. Therefore, despite the inherent tradeoff between the transparency and the piezoelectricity, numerous strategies have been explored to develop the transparent piezoelectric materials. Nonetheless, the most transparent piezoelectric materials developed to date is either a single crystal or materials that achieve transparency via hot-press sintering, limiting its industrial applicability. Therefore, we introduce a novel piezoelectric material that ensures transparency through co-doping and pressureless sintering of polycrystalline ceramics. In this study, we employed a compositional optimization approach to enhance the synergistic effect between the transparency and the piezoelectric properties of 0.71Pb(Mg_1/3Nb_2/3)O₃–0.29PbTiO₃ (PMN–0.29PT) ceramics. By utilizing the tape casting process for mass production and large-area manufacturing, our Pb_0.913La_0.0145Sm_0.0145(Mg_1/3Nb_2/3)_0.71Ti_0.29O₃ (TP2.9) ceramics exhibited over 60% transparency and large piezoelectric coefficient (d₃₃) of 1104 pC/N. This material holds considerable promise for a wide range of industrial applications in both the optical and electronic domains.