Effects of sintering temperature on the properties of donor-acceptor codoped Ba_(0.67)Sr_(0.33)TiO_3 ceramics for pyroelectric infrared detector applications

摘要

Ba_(0.67 - x)Y_xSr_(0.33)Ti_(1 - y)Mn_yO_3 [(Mn+Y: BST), x=0.006, y=0.005] ceramics were fabricated via using citrate-nitrate combustion derived powder, and their microstructure, dielectric properties and pyroelectric properties were systemically investigated within sintering temperature ranged from 1200 ℃ to 1310 ℃. Slight agglomerated BST powders, with nano-size parties, were produced at calcining temperature of 800 ℃. Sintering temperature has a great influence on the microstructure and electrical properties of the ceramic samples. The dielectric and pyroelectric properties are improved with sintering temperature increased from 1200 ℃ to 1280 ℃. At room temperature, the Mn+Y: BST ceramics sintered at 1280 ℃ for 3 h exhibit optimal electrical properties: dielectric loss tan δ=0.007, intrinsic pyroelectric coefficient γ=773 nC/ cm~2 K and figure-of-merit F_D= 134.5 μPa~(-0.5) at 100 Hz, respectively. Improvement of pyroelectric properties is beneficial to the development ofinfrared detectors.