Large electric-induced pyroelectric properties in (Pb_0.87La _0.02Ba_0.1) (Zr_0.7Sn_0.24Ti _0.06)O₃ antiferroelectric ceramics with excess PbO

(Pb_0.87La_0.02Ba_0.1) (Zr _0.7Sn_0.24Ti_0.06)O₃ (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 μC/m²K to 4000 μC/m ²K, and the figure of merit increased from 40× 10^-5 Pa^-0.5 to 140 ×10^-5 Pa^-0.5 under a 400 V/mm dc field. The largest figure of merit of 200 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.