Effect of Sb doping on pyroelectric properties of KNN‐based ceramics

Abstract The objective of this study was to investigate the effects of Sb doping on the pyroelectric properties of K x Na 1 − x NbO 3 (KNN)‐based ceramics, focusing on changes in microstructure and physical properties such as dielectric constant, piezoelectric coefficient, dielectric loss, mechanical quality factor, and so forth. The KNN‐based ceramic codoped with Li and BF (BiFeO 3 ) system, featuring high Curie temperature and superior pyroelectric performance, was selected for Sb doping. The research results indicate that the addition of an appropriate amount of antimony (Sb) effectively shifts the O and T phase transitions of KNN‐based ceramics closer to room temperature, thereby enhancing the system's polarization capability, remanent polarization, and response to temperature, consequently elevating its pyroelectric performance. Moreover, the introduction of Sb broadens the phase transition temperature range, contributing to the maintenance of pyroelectric properties over a wider temperature range around room temperature. Consequently, the x  = 2% composition (99.5%(K 0.5 Na 0.5 ) 0.95 Li 0.05 Sb x Nb 1 − x O 3 –0.5%BiFeO 3 ) exhibits an optimal pyroelectric coefficient p (705 µC m −2 K −1 ) at room temperature and demonstrates excellent figures of merit (FOMs): F i  = 2.90 × 10 −10  m V −1 , F v  = 0.032 m 2 C −1 , F d  = 1.791 × 10 −5  Pa −1/2 , along with a high Curie temperature (390°C), making it a commercially valuable KNN‐based material for pyroelectric infrared radiation detectors.