Effect of bulk porosity on the pyroelectric properties of Na0.5Bi0.5TiO3–0.06BaTiO3 ceramics

Abstract

Numerous efforts have been made to improve the pyroelectric properties of lead-free ceramics through doping/substitution, nonstoichiometry, porosity and composite formation. Hence, the bulk porous Na0.5Bi0.5TiO3–0.06BaTiO3 (NBT–6BT) ceramics were prepared to obtain enhanced pyroelectric properties and figures of merit for energy harvesting. For this purpose, the burnt-out polymer technique was used to obtain the desired porosity via 0–12% poly(methyl methacrylate) polymer addition. The dielectric constant for the unpoled and poled samples decreased from 2215 to 422 and 790 to 221, respectively, as the porosity increased from 6 to 30%. The pyroelectric coefficient was also examined at room temperature to show an increment from 4.8 to 6.62 × 10−4 C/m2 K with increasing porosity from 6 to 10%. Pyroelectric figures of merit, i.e., voltage responsivity (~ 47.16 × 10−3 m2/C) and energy harvesting (~ 78.75 J/m3K2), were observed to be highest for NBT–6BT (2 wt% PMMA) at room temperature. The findings suggest that the porous structure can enhance the pyroelectric properties of lead-free ceramics. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.