Primary Pyroelectricity in Barium Titanate Ceramics

Data have been obtained on the pyroelectric and piezoelectric behavior of samples of a polycrystalline barium titanate ceramic in an effort to determine the possible existence of a primary pyroelectric effect. It is shown that the total pyroelectric effect is in a direction opposite to the piezoelectric contribution resulting from volumetric changes and that, as a consequence, there must exist a primary pyroelectric effect. The time constant of the samples for generation of electrical signals from heat pulses was less than 12 μsec. Practical applications of barium titanate sensors may be found in the measurement of heat radiation beams having large cross sections.