High pyroelectric performance in Pb0.99Nb0.02[(Zr0.57Sn0.43)0.94Ti0.06]0.98O3/Al2O3 composites by design

High pyroelectric performance around human body temperature is essential for ultra-sensitive infrared detectors of medical systems. Herein, toward human health monitoring, composite ceramics (1- x )Pb 0.99 Nb 0.02 [(Zr 0.57 Sn 0.43 ) 0.94 Ti 0.06 ] 0.98 O 3 / x Al 2 O 3 ( x = 0, 0.1, and 0.2) were designed. A metastable ferroelectric (FE) phase was induced in the anti-FE matrix by the Al 2 O 3 component-induced internal stress, and in turn FE-anti-FE phase boundary was constructed. The ceramics at x = 0.2 exhibit high pyroelectric coefficient with p = 10.9 × 10 −4 C·m −2 ·K −1 and figures of merit with current responsivity F i = 6.23 × 10 −10 m·V −1 , voltage responsivity F v = 12.71 × 10 −2 m 2 ·C −1 , and detectivity F d = 7.03 × 10 −5 Pa −1/2 around human body temperature. Moreover, the enhanced pyroelectric coefficients exist in a broad operation temperature range with a large full width at half maximums of 18.5°C and peak value of 29.2 × 10 −4 C·m −2 ·K −1 at 48.2°C. The designed composite ceramic is a promising candidate for infrared thermal imaging technology of noncontact human health monitoring system.