Investigation of the electrical properties of (1-x)Pb(Mg1/3Nb2/3)O-3-xPbTiO(3) single crystals with special reference to pyroelectric detection

摘要

The pyroelectric properties of relaxor-based ferroelectric single crystals (1 - x)Pb(Mg1/3Nb2/3)O-3-xPbTiO(3) (PMN-xPT) with 0.13 <= x <= 0.40 were investigated for infrared detectors and imagers. The optimized compositions, crystallography orientations and thermal treatment temperature have been confirmed. The results show that [1 1 1] oriented rhombohedral PMN-xPT with 0.26 <= x <= 0.28 possess superior pyroelectric performances with high figures of merit (FOM) for the current responsivity F-i similar to 600 pm V-1, voltage responsivity F-v similar to 0.11 m(2) C-1 and detectivity F-d similar to 15 x 10(-5) Pa-1/2 at room temperature. The pyroelectric properties are relatively independent of the temperature between 15 and 70 degrees C while they dramatically degrade with T > 80 degrees C. Future infrared detector and imager designs can rely on PMN-xPT single crystals with 0.26 <= x <= 0.28 offering outstanding pyroelectric performance under operational conditions of T < 70. C. [0 0 1] oriented PMN-xPT single crystals with x similar to 0.37 offer relatively lower FOM but higher phase transition temperature and weaker temperature dependence of the pyroelectric properties. Therefore, it is required to select a composition of PMN-xPT single crystals for device application according to the application environment and the performance requirement.