Pyroelectric properties of (Ba1-xCdx)(Zr0.13Ti0.87)O3 ferroelectric ceramics in polymorphic state

Abstract

Ceramic compositions of (Ba1-xCdx)(Zr0.13Ti0.87)O3 with x = 0, 0.02, 0.04 and 0.06 exhibit a layered microstructure and enhanced grain growth (~ 50 µm for x = 0.06). The XRD and Raman measurements reveal the coexistence of rhombohedral, orthorhombic and tetragonal phase, and with increase in Cd content the rhombohedral phase fraction increases significantly (10–56%) whereas the phase fraction of tetragonal decreases (62–14%). Pyroelectric coefficient (p) increases with Cd content and a large value of p ~ 1841 μCm−2 K−1 is obtained for x = 0.06. Current responsivity Fi is maximum (~ 849 pmV-1) for x = 0.02, whereas the voltage responsivity Fv (~45 ×10−3 m2 C−1), detectivity Fd (~48 μPa−1/2) and thermal energy harvesting figure of merit Fe* (~34 pJ−1 m3) are maximum for x = 0.06. Ease of polarization rotation in the polymorphic state due to the coexistence of rhombohedral, orthorhombic and tetragonal phases, and a large ceramic grain size contribute to the strong pyroelectric response.