Pyroelectric performance of porous Ba_0.85Sr_0.15TiO₃ ceramics

Abstract

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 (FOMs).

Scavenging Energy Sources Using Ferroelectric Materials

“…The F D , F E , and F V of the porosity of 29.5% were increased by 19%, 61%, and 210% compared with the dense counterpart. [158] Yang et al fabricated (1-x)K 0.5 Na 0.5 NbO 3 -xBi 0.5 Na 0.5 ZrO 3 (KNN-xBNZ) ceramics with a PPT region, which is achieved near room temperature by modification through doping. The pyroelectric coefficient of KNN-0.03BNZ is p ≈ 454.46 × 10 −4 C m −2 K −1 at the T C and the figures of merit F I , F V , F D , and F E of KNN-0.03BNZ at room temperature are 1.83 × 10 −-9 m V −1 , 0.17 m 2 C −1 , 0.34 × 10 −4 Pa −1/2 , and 5.3 J m −3 K −1 , respectively.…”

Diesel Exhaust Emission Soot Coated Pyroelectric Materials for Improved Thermal Energy Harvesting

“…This technique seems to have better efficiency than the known other sister techniques such as thermoelectric energy harvesting. Various concepts have been demonstrated for pyroelectric energy harvesting . Although results are promising, still these materials are only sufficient for low power electronic devices.…”

“…Various concepts have been demonstrated for pyroelectric energy harvesting. [6][7][8] [2,[9][10][11] In order to improve the performance, several strategies such as inducing porosity, tuning pyroelectric coefficient, and some other physical techniques have been proposed. [1,6,12,13] Very recently few studies were attempted for surface modification which ultimately improved thermal properties.…”

“…[6][7][8] [2,[9][10][11] In order to improve the performance, several strategies such as inducing porosity, tuning pyroelectric coefficient, and some other physical techniques have been proposed. [1,6,12,13] Very recently few studies were attempted for surface modification which ultimately improved thermal properties. [14][15][16] These thermal properties ultimately control heating and cooling of sample as pyroelectric current is directly typical peaks at 1350, 1470, and 1580 cm -1 .…”

“…Large number of materials such as BaCa x Ti 1‐ x O 3 , Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 , PbZr x Ti 1‐ x O 3 , BaTi 1‐ x Sn x O 3 have been examined for energy harvesting applications . In order to improve the performance, several strategies such as inducing porosity, tuning pyroelectric coefficient, and some other physical techniques have been proposed . Very recently few studies were attempted for surface modification which ultimately improved thermal properties .…”