High Pyroelectric Properties of Porous Ba0.67Sr0.33TiO3 for Uncooled Infrared Detectors

Porous Ba0.67Sr0.33TiO3 (BST) ceramics were fabricated by the solid-state reaction process, and their micro-structural, dielectric, and pyroelectric properties were systemically investigated. Compared with dense specimens, porous BST exhibited a higher pyroelectric coefficient (p), a lower dielectric constant (e), and heat capacity (CV), which are beneficial for the development of pyroelectric devices. At room temperature, as the porosity increased from 1.0% to 9.6%, BST ceramics' pyroelectric coefficient increased from 5000 to 8000 mu c.(m(2).degrees C)(-1), the dielectric constant decreased from 12 000 to 8000, while the dielectric losses were <1.0% and the figure-of-merit F-D = p/C-v root epsilon tan delta increased from 11.0 x 10(-5) to 27.0 x 10(-5) Pa-0.5. Improvement of pyroelectric property is benecial for the development of infrared detectors.