Pyroelectric properties of rhombohedral and tetragonal Pb(In1/2Nb1/2)-Pb(Mg1/3Nb2/3)-PbTiO3 crystals

Abstract

Pyroelectric properties of rhombohedral and tetragonal single crystals Pb(In1/2Nb1/2)-Pb(Mg1/3Nb2/3)-PbTiO3 (PIN-PMN-PT) were investigated, with temperature from −100 °C to 100 °C. At room temperature, the pyroelectric coefficient p and the figure of merit Fd of rhombohedral crystals are 7.81 × 10−4 C/m2 K and 10.9 × 10−5 Pa−1/2, respectively, and 6.84 × 10−4 C/m2 K and 11.67 × 10−5 Pa−1/2, respectively, for tetragonal crystals. Although the coefficient p and Fd at room temperature are similar for rhombohedral and tetragonal crystals, the Fd of tetragonal crystal is much more stable with respect to temperature, owing to its higher phase transition temperature and stable mono-domain state. From room temperature to 100 °C, the Fd of rhombohedral crystal decreases from 10.74 × 10−5 Pa−1/2 to 5.3 × 10−5 Pa−1/2, while that of tetragonal crystals is nearly independent of temperature. Such investigation reveals that tetragonal PIN-PMN-PT crystal is more suitable for uncooled infrared detectors and imagers when compared with its rhombohedral counterpart.