Large pyroelectric response in relaxor-based ferroelectric (1−x)Pb(Mg1∕3Nb2∕3)O3–xPbTiO3 single crystals

Abstract

The pyroelectric properties of (1−x)Pb(Mg1∕3Nb2∕3)O3–xPbTiO3 (PMN–xPT) single crystals have been investigated over a broad composition range of 0.13⩽x⩽0.40. The best pyroelectric performances are achieved in ⟨111⟩-oriented PMN–0.26PT single crystal. At room temperature, the figures of merit for voltage responsivity and detectivity reach up to 0.11m2∕C and 15.3×10−5Pa−1∕2, respectively. These properties are superior to those of conventional pyroelectric ceramics that have been widely used in device applications. PMN–0.26PT single crystal also possesses a relative high Curie temperature (∼120°C) and a low thermal diffusivity (∼4.4×10−7m2∕s). Furthermore, the pyroelectric properties of PMN–xPT (x⩾0.26) single crystals are weak dependent on temperature and nearly independent of frequency in the experimental temperature range of 20–55°C and frequency range of 50–10000Hz. The superior pyroelectric performances of the single crystal make it a promising candidate for high-performance uncooled infrared detectors and thermal imagers.