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

Multifunctional ceramics with good dielectric, ferroelectric, piezoelectric and photoluminescence properties have been fabricated at a low sintering temperature of 960 degrees C. Via the addition of Li2CO3, oxygen vacancies are produced in the Pr-doped 0.93(Bi0.5Na0.5) TiO3-0.07BaTiO(3) ceramics, which can enhance the ionic lattice-diffusion coefficient, promote the densification and thus lower the sintering temperature effectively from 1200 to 960 degrees 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. (c) 2017 Elsevier B.V. All rights reserved.