Pyroelectric properties of lead-free ferroelectric niobium-rich potassium lithium tantalate niobate single crystals

The pyroelectric properties of niobium-rich potassium lithium tantalate niobate K0.95Li0.05Ta1−xNbxO3 (x=0.46, 0.51, 0.55, and 0.62) single crystals have been investigated. The pyroelectric coefficients (pi), the computed spontaneous polarizations (Ps) and the pyroelectric figures of merit (FOMs) have been determined. The typical values of pi (632 μC/cm2 K), Ps (13.3 μC/cm2) and FOM (243 pm/V) are attractive, and can be compared to the classical pyroelectric materials. The transition temperatures also have been determined from dielectric and pyroelectric measurements. These good pyroelectric properties as well as the possibility to produce large-size and high-quality single crystals make this kind of single crystal very promising for infra-red detectors and other pyroelectric applications.