IR DETECTORS USING PB(MG1/3NB2/3)O3 AND PB(SC1/2TA1/2)O3 CERAMICS UNDER DC BIAS

Recently, one type of thermal-type IR detector, the pyroelectric sensor, has become of great interest in commercial applications, because of its ability to operate without cooling, its constant detectivity independent of wavelength, and its low cost. The conventional pyroelectric materials are usually normal ferroelectric materials with a first and second phase transition. The working temperatures are sufficiently below the Curie temperature T(c) for stable responsitivity to temperature. Electric field induced-type pyroelectric sensors have also been proposed. Relaxor ferroelectric materials such as Pb(Mg1/3Nb2/3)O3 (PMN) and Pb(Sc1/2Ta1/2)O3 (PST), which have a glassy Curie temperature near room temperature, are used in this type of sensor.