A dynamic technique for studying the pyroelectric effect and its application to ferroelectrics

A dynamic technique for studying the pyroelectric effect has been developed. Pyroelectric current pulses of approximately square waveform are produced in pyroelectric crystals when they are illuminated with intense chopped light from a tungsten lamp. During a light pulse the crystal temperature, T, rises, thus causing the polarization, P, to change at a rate determined by the product of the pyroelectric coefficient, (dP/dT), and the rate of change of temperature, (dT/dt). This steady change in the polarization is manfested as a current pulse in the measuring circuit. The magnitude and direction of the current are determined, primarily, by the net pyroelectric coefficient and the direction of the net polarization of the crystal, respectively. The technique is a sensitive and non-destructive method for studying the state of the polarization of the crystal.