Large electric-induced pyroelectric properties in (Pb0.87La0.02Ba0.1) (Zr0.7Sn0.24Ti0.06)O3 antiferroelectric ceramics with excess PbO

(Pb0.87La0.02Ba0.1) (Zr0.7Sn0.24Ti0.06)O-3 (PLBZST) antiferroelectric ceramics with the addition of 0-9 wt. % excess PbO were fabricated by the conventional solid-state reaction process, and their microstructure, dielectric, and pyroelectric properties were systemically investigated. When excess PbO content was less than 9 wt. %, two pyrochlore phases were formed along with the perovskite phase. Compared with common specimens, PLBZST antiferroelectric ceramics with excess PbO exhibited a higher pyroelectric coefficient and a lower dielectric loss, which are beneficial for the development of pyroelectric devices. Around the Curie temperature, as the excess PbO increased from 0 wt. % to 9 wt. %, PLBZST ceramics' pyroelectric coefficient increased from 1600 mu C/m(2) K to 4000 mu C/m(2) K, and the figure of merit increased from 40 x 10(-5) Pa-0.5 to 140 x 10(-5) Pa-0.5 under a 400 V/mm dc field. The largest figure of merit of 200 x 10(-5) Pa-0.5, which is about 8 times higher than that of conventional phase transition materials barium strontium titanate (BST), was obtained in PLBZST ceramics with 6 wt. % excess PbO when a 600 V/mm dc bias field was applied. Therefore, improvement of pyroelectric property is beneficial for the development of infrared detectors. (C) 2011 American Institute of Physics. [doi:10.1063/1.3596577]