Enhanced pyroelectric figure of merits of porous BaSn0.05Ti0.95O3 ceramics

Porous BaSn0.05Ti0.95O3 (BTS) ceramics were prepared by sintering compacts consisting of BTS and Poly (methyl methacrylate)(PMMA)as pore former. Porous BTS ceramics were systematically characterized for microstructural, ferroelectric, dielectric and pyroelectric properties. Porosity increased from 4% to 22.5% with increasing PMMA content. Dielectric constant decreases and loss increases with porosity. At 22.5% porosity, relative dielectric constant of BTS decreased by 47% (from 2525 to 1335) at 1 MHz/303K. Porosity leads to significant reduction in dielectric constant and volume specific heat capacity, which are of great interest for improving pyroelectric figure of merits (FOMs). Further, FOMs for current responsivity (Fi), voltage responsivity (Fv), detectivity (Fd) and energy harvesting (Fe and Fe*) are calculated. Compared with dense ceramic, 2% PMMA specimen showed an improvement of Fe by 166% and Fe*by 177%. Fv increased by 77%, Fd by 73% and Fi by 56% at 303K. All of these advancements are favorable for pyroelectric device applications.