Low-temperature-sintered Pr-doped 0.93(Bi0.5Na0.5)TiO3-0.07BaTiO3 multifunctional ceramics with Li2CO3 sintering aid

Abstract

Multifunctional ceramics with good dielectric, ferroelectric, piezoelectric and photoluminescence properties have been fabricated at a low sintering temperature of 960 °C. Via the addition of Li2CO3, oxygen vacancies are produced in the Pr-doped 0.93(Bi0.5Na0.5)TiO3-0.07BaTiO3 ceramics, which can enhance the ionic lattice-diffusion coefficient, promote the densification and thus lower the sintering temperature effectively from 1200 to 960 °C. The Li-addition also induces lattice distortion and expansion, which strengthen the internal field among the polar nano-regions of the ceramic. As a result, the depolarization temperature is increased and the room-temperature piezoelectric properties are enhanced. Moreover, the structural symmetry is reduced, and thus leading to an increase in the uneven components of the crystal fields around Pr3+ and then an enhancement in photoluminescence emissions. Together with the good dielectric properties assured by the dense structure, the ceramics are ready for use in multifunctional optoelectronic applications.