CaxSr0.3−xBa0.7Nb2O6 lead-free pyroelectric ceramics with high depoling temperature

Abstract

CaxSr0.3−xBa0.7Nb2O6 [CSBN (x), x = 0.00, 0.10, 0.20, and 0.30] lead-free ceramics were fabricated by traditional solid-state reaction technique. The morphology, structure, dielectric, ferroelectric and pyroelectric properties of CSBN (x) ceramics were systematically studied. The thermal depoling behaviors were evaluated through measurements of temperature dependence of piezoelectric constant (d33). All CSBN (x) ceramics exhibited obvious diffuse phase transitions and maximum dielectric constant (εm) increased monotonically with x. The ferroelectric and pyroelectric properties of CSBN (x) have been enhanced remarkably due to Ca addition. The remnant polarization (Pr) and pyroelectric coefficient (p) of CSBN (0.30) samples reached 4.95 μC/cm2 and 1.30 × 10−8C/cm2K which roughly tripled and doubled pure SBN. What's more, CSBN (0.20) samples achieved rather high pyroelectric figure of merit of voltage (Fv = 0.0203 m2/C) which is superior to many other lead-free materials and pyroelectric figure of merit of detectivity (FD) for CSBN (0.20) and CSBN (0.30) samples both soared to 0.61 × 10−5Pa−1/2. The most inspiring part is the depoling temperature and Curie temperature noticeably shifted to higher temperature region owing to Ca addition. These results unveil the potential of CSBN (x) ceramics for infrared detector applications.