Dielectric and pyroelectric properties of ultrathin, monocrystalline lithium tantalate

Ultrathin, self-supporting lithium tantalate (LiTaO3) wafers have been fabricated out of a single crystal with a minimum thickness of about 0.4 μm using ion-beam milling. The most decisive parameters (pyroelectric coefficient, relative permittivity, and dielectric loss factor) for their use in pyroelectric radiation detectors were studied in dependence on film thickness and temperature. The potential performance of pyroelectric materials was evaluated using appropriate figures of merit. In addition, the dielectric and pyroelectric properties of stoichiometric LiTaO3 were investigated and compared to congruent LiTaO3 bulk material conventionally used for pyroelectric detectors.