Pyroelectric performance of porous Ba 0.85 Sr 0.15 TiO 3 ceramics

Porous Ba 0.85 Sr 0.15 TiO 3 ( BST ) ferroelectric ceramics were synthesized by sintering compacts consisting of BST and Poly(methyl methacrylate) ( PMMA) (2%, 4%, 6%, 8%, and 10% by wt.) as pore‐forming agent. Systematic investigation of role of porosity on microstructural, dielectric, and pyroelectric performance is carried out. It is observed that as PMMA increased from 0% to 10%, the porosity increased from 7.5% to 29.5%. Dielectric constant decreases and dielectric loss increases with increasing PMMA content at fixed frequency. When porosity reached 29.5%, the relative dielectric constant of the BST composition decreased by more than 78% (from 3500 to 750) at 10 kHz and 300 K. Porosity leads to a significant reduction in dielectric constant and volume‐specific heat capacity, which are of great interest for improving pyroelectric figure of merits ( FOM s). Further, the pyroelectric figure of merits for current responsivity ( F i ), voltage responsivity ( F v ), detectivity ( F d ), and energy harvesting ( F e and F e *) are calculated for all investigated compositions. Compared with dense ceramic, porous BST (10% PMMA ) showed an improvement of F d by 19%, F e by 61%, and F e * by 98%. F v increased by 210% at 300 K/10 kH z. All of these advancements are favorable for the development of pyroelectric devices.