The use of lead-free materials has recently become a very important issue in environmental protection of the earth. Two groups of lead-free ceramics, (K0.5, Na0.5) NbO3based (KNN) and Bi1-y (Nax K1-x)y TiO3based (BNKT), were studied for their thermal, dielectric, and pyroelectric properties as candidates for pyroelectric sensor applications. The BNKT-based ceramic, [Bi0.5(Na0.94K0.05Li0.016)0.5]0.95Ba0.05TiO3(BNKLBT), shows excellent pyroelectric properties when compared with KNN-based ceramic and lead zirconate titanate. Its properties were measured as follows: pyroelectric coefficient p=360 μC m2K, pyroelectric figure of merit of current, voltage, and detectivity Fi=221 pmV, Fv=0.030 m2C, and Fd =14.8 μ Pa-12. With these outstanding pyroelectric properties, the BNKLBT ceramic can be a promising material for pyroelectric sensor applications. The BNKLBT ceramic with different thicknesses (i.e., 0.3, 0.5, and 0.7 mm) have been used as the sensing element for fabricating infrared detectors. The current responsivity of the sensors was evaluated as functions of frequency.
ASJC Scopus subject areas
- Physics and Astronomy(all)